Updated November 7th: Here are the Scott catalogue numbers:
Sc. 5247-5250
5247 “Deck the Halls”
5248 “Silent Night”
5249 “Jingle Bells”
5250 “Jolly Old St. Nicholas”
5250a block of 4
5250b booklet pane of 20
Updated September 13th: Here are the first-day postmarks for this issue: 
The Digital Color Postmark for this issue measures 2.27” x 1.45″. 
The B&W pictorial (rubber) postmark measures 2.99” x 1.70”.
Updated September 3rd:
On October 5, 2017, in New York, NY, the U.S. Postal Service will issue Christmas Carols stamps (Forever priced at 49 cents) in four designs, in a pressure-sensitive adhesive (PSA) booklet of 20 stamps (Item 677300). The stamps will go on sale nationwide October 5, 2017.
In 2017, the U.S. Postal Service celebrates the Christmas season with four new Forever stamps featuring images that illustrate a major theme from four beloved Christmas carols:
- “Jingle Bells,”
- “Deck the Halls,”
- “Silent Night,” and
- “Jolly Old Saint Nicholas.
Familiar lines from each song highlight the individual stamps. The shades of blue in the background of the stamps evoke the evening scenes from the four carols. This booklet of 20 stamps includes five of each design. The late Howard E. Paine was the art director and artist Steve McCracken created the original art for this project.
Availability to Post Offices: Item 677300, $9.80 Christmas Carols (Forever priced at 49 cents) Double-sided Booklet of 20 Stamps
Stamp Fulfillment Services will make an automatic push distribution to Post Offices of a quantity to cover approximately 30 days of sales.
How to Order the First-Day-of-Issue Postmark:
Customers have 60 days to obtain the first-day-of-issue postmark by mail. They may purchase new stamps at their local Post Office, at The Postal Store« website at usps.com/shop, or by calling 800-782-6724. They must affix the stamps to envelopes of their choice, address the envelopes (to themselves or others), and place them in a larger envelope addressed to:
Christmas Carols Stamps
USPS Stamp Fulfillment Services
8300 NE Underground Drive, Suite 300
Kansas City, MO 64144-9900
After applying the first-day-of-issue postmark, the Postal Service” will return the envelopes through the mail. There is no charge for the postmark up to a quantity of 50. There is a 5-cent charge for each additional postmark over 50. All orders must be postmarked by December 5, 2017.
Philatelic products for this stamp issue are as follows:
- 677306, Press Sheet with Die-cut, $78.40.
- 677310 Digital Color Postmark Keepsake (set of 4), $16.95.
- 677316 First-Day Cover (set of 4), $3.72.
- 677321 Digital Color Postmark (set of 4), $6.56.
- 677324 Framed Art, $29.95.
- 677330 Ceremony Program, $6.95.
Technical Specifications:
Issue: Christmas Carols Stamps
Item Number: 677300
Denomination & Type of Issue: First-Class Mail« Forever
Format: Double-sided Booklet of 20 (4 designs)
Series: N/A
Issue Date & City: October 5, 2017, New York, NY 10199
Art Director: Howard E Paine
Designer: Howard E Paine
Typographer: Howard E Paine
Artist: Steve McCracken, Winchester, VA
Modeler: Sandra Lane/Michelle Finn
Manufacturing Process: Offset
Printer: Banknote Corporation of America
Printed at: Browns Summit, NC
Press Type: Alprinta 74
Stamps per Booklet: 20
Print Quantity: 900,000,000 stamps
Paper Type: Phosphor Tagged Paper, Block
Adhesive Type: Pressure-sensitive
Processed at: Banknote Corporation of America, Browns Summit, NC
Stamp Orientation: Horizontal
Image Area (w x h): 1.05 x .77 in/26.67 x 19.56 mm
Stamp Size (w x h): 1.19 x .91 in/30.23 x 23.11 mm
Full Booklet Size (w x h): 2.375 x 5.743 in/60.33 x 145.87 mm
Press Sheet Size (w x h): 9.5 x 11.486 in/241.30 x 291.74 mm
Colors: Cyan, Magenta, Yellow, Black
Plate Size: 800 stamps per revolution
Plate Numbers: “B” followed by four (4) single digits
Marginal Markings: Header “Christmas Carols” 20 First-Class Forever Stamps • Plate numbers in peel strip area • © 2016 • USPS in peel strip area • Barcode
Updated March 13th: The USPS says these stamps will be issued October 5 in New York, which would coincide with the ASDA stamp show.
From the USPS, November 22nd, 2016:
The 2017 Christmas season will be celebrated with four new Forever stamps featuring images that illustrate four beloved Christmas carols: “Jingle Bells,” “Deck the Halls,” “Silent Night,” and “Jolly Old Saint Nicholas. ” Familiar lines from each song highlight the individual stamps. Shades of blue in the stamp backgrounds evoke the evening scenes from the four carols. This booklet of 20 stamps includes five of each design. The late Howard E. Paine was art director; artist Steve McCracken created the original art. 
WHAT:
WHEN:
The U.S. Postal Service showcases Ezra Jack Keats’ most beloved story, The Snowy Day. Written and illustrated by the celebrated children’s author, it was one of the first prominent 20th-century picture books centered on an African-American child. Each of the four new stamps in this 20-stamp booklet features a different illustration of main character Peter exploring and playing in his neighborhood while wearing his iconic red snowsuit. The images include Peter forming a snowball; sliding down a mountain of snow; making a snow angel; and leaving footprints in the snow. Art director Antonio Alcalá of Alexandria, VA, designed the stamps. The stamps may be pre-ordered in early Sept. for delivery shortly after the Oct. 4 issuance at usps.com/shop.
The Digital Color Postmark measures 3″x2.232″. 
The B&W pictorial (rubber) postmark measures 2.353″ x 1.5”. 
The special postmark for use by other post offices measures 2.7” x 1.232”.
WHAT:
BACKGROUND:
It measures 2.90″ x 1.45″.
It measures 2.93″ x 1.38″. Here is the black-and-white pictorial: 
It measures 2.97″ x 0.48″.
On May 23, 2017, in Concord, MA, the U.S. Postal Service® will issue the Henry David Thoreau stamp (Forever® priced at 49 cents), in one design, in a pressure-sensitive adhesive (PSA) pane of 20 stamps (Item 475100). The stamp will go on sale nationwide May 23, 2017.
Format: Pane of 20 (1 design)
With his personal example of simple living, his criticism of materialism and the questions he raises about the place of the individual in society and humanity’s role in the natural world, Henry David Thoreau (1817-1862) continues to inspire readers. For 26 months, Thoreau lived in a one-room house on a lake just outside his hometown of Concord, MA, writing prolifically while farming, reading, thinking, taking long walks and observing nature around him. “Walden,” the 1854 book he wrote about his experience, still holds the attention of readers by blending elements of numerous genres to create a complex, eclectic and unique work. Art director Greg Breeding designed this stamp with original art by Sam Weber. 
On July 12, 2017, in Chadds Ford, PA, the U.S. Postal Service® will issue the Andrew Wyeth stamps (Forever® priced at 49 cents), in twelve designs, in a pressure-sensitive adhesive (PSA) pane of 12 stamps (Item 475000). The stamps will go on sale nationwide July 12, 2017.
This issuance includes 12 stamps that feature a detail of a different Andrew Wyeth painting. The paintings are: “Wind from the Sea” (1947), “Big Room” (1988), “Christina’s World” (1948), “Alvaro and Christina” (1968), “Frostbitten” (1962), “Sailor’s Valentine” (1985), “Soaring” (1942–1950), “North Light” (1984), “Spring Fed” (1967), “The Carry” (2003), “Young Bull” (1960), and “My Studio” (1974). The selvage shows a photograph of Wyeth from the 1930s. Art director Derry Noyes designed the pane.
Issue: Andrew Wyeth Stamps
Mastering a realistic style that defied artistic trends, Andrew Wyeth (1917-2009) created haunting and enigmatic paintings based largely on people and places in his life — a body of work that continues to resist easy or comfortable interpretation. Finding endless inspiration both in his hometown of Chadds Ford, PA, and in rural Maine, he scrutinized the lives, houses and personal belongings of people around him, sometimes painting their portraits but just as often using objects and places to represent them. 2017 is the centennial of Wyeth’s birth. With subtle symbolism and eerie implications, his work invites us to reinterpret his personal vision. Derry Noyes art directed and designed this pane of 12 stamps.
On June 14, 2017, in Hartford, WI, the U.S. Postal Service® will issue the Have a Ball! stamps (Forever® priced at 49 cents), in eight designs, in a pressure-sensitive adhesive (PSA) pane of 16 stamps (Item 474900). The Have a Ball! $7.84 pane of 16 stamps may not be split, and the stamps may not be sold individually. The stamps will go on sale nationwide June 14, 2017.
It measures 2.94″x1.18″.
On April 11, 2017, in Rochester, NY, the U.S. Postal Service will issue the Robert Panara two ounce rate mail use stamp (Nondenominated, priced at 70 cents) in one design, in a pressure-sensitive (PSA) pane of 20 stamps (Item 114000). The stamp will go on sale nationwide April 11, 2017.
WHAT:
BACKGROUND:
The U.S. Postal Service commemorates the 200th anniversary of Mississippi becoming the 20th state on Dec. 10, 1817. The Mississippi Statehood Forever stamp features a photograph taken by Lou Bopp in 2009. It shows a close-up of a musician’s hands as he plays his guitar. Mississippi is the birthplace of many legendary blues artists who created a uniquely American genre of music.
This stamp celebrates the 200th anniversary of Mississippi statehood. Mississippi became the 20th state on Dec. 10, 1817. The stamp features a 2009 photograph showing a close-up of a guitar player hands. Mississippi is the birthplace of many legendary blues artists who created a uniquely American genre of music. Among states, the Magnolia State is 32nd in size, and with nearly three million people, it ranks 31st in population. Art director Greg Breeding designed the stamp with an existing photo taken by Lou Bopp.
It measures 2.93″ x 1.38″. There is also a pictorial first-day postmark: 
Although it looks virtually identical, we’re told it measures 2.97″ x 1.48″.
When:
It measures 2.93″ x 1.38″.
Tuesday, May 2, 2017, 11 a.m.
