From the USPS July 28th:

This new stamp celebrates the joyous Jewish holiday of Hanukkah. The stamp art’s colorful digital illustration shows the lighting of the nine-branched Hanukkah menorah on the last evening of the holiday. All eight of the Hanukkah candles have been lit, and the child is reaching up to replace the shamash, the helper candle used to light the others in the menorah. Art director Ethel Kessler designed the stamp with original art by Jing Jing Tsong.

This stamp will be issued Tuesday, October 6, with a first-day city of New Rochelle, NY. New information will appear below the line, with the latest at the top. Hanukkah in 2020 begins the evening of December 10th and ends at sundown on December 18th.

Updated December 5th:
The Scott catalogue number for this issue is 5530.

Updated September 29th:
Virtual ceremony for this issue.

[press release]
New Stamp Celebrates Hanukkah

WHAT: The U.S. Postal Service announces a new stamp dedicated to the festive Jewish holiday Hanukkah.

Families come together each year to celebrate Hanukkah, also called the Festival of Lights. In 2020, Hanukkah begins on the evening of Dec. 10.

News of the stamp is being shared with hashtag #HanukkahStamps.

WHO: USPS Controller and Vice President Cara Greene

Union for Reform Judaism Senior Vice President Emeritus Rabbi Lennard Thal
Artist Jing Jing Tsong

WHEN: Tuesday, Oct. 6, 2020, at 11 a.m. EDT

WHERE:
A virtual stamp dedication ceremony for the Hanukkah stamp will be posted on the Postal Service’s Facebook and Twitter pages.

Please visit usps.com/hanukkah for details of the event.

BACKGROUND:

The stamp art’s colorful digital illustration shows the lighting of the hanukiah on the last evening of Hanukkah. Artist Jing Jing Tsong chose her colors intentionally to evoke Hanukkah traditions as seen through the eyes of children.

The darker blue colors in the background symbolize winter, while the brightly colored flaming candles reflect the spirit and warmth of sharing the holiday traditions.

The Hanukkah stamp is being issued as a Forever stamp in a pane of 20. This Forever stamp will always be equal in value to the current First-Class Mail 1-ounce price.
Pre-orders for the Hanukkah stamp can be placed online at usps.com and by phone at 800-STAMP24 (800-782-6724).

Updated September 3rd:
Here are the first-day postmarks for this issue: The Digital Color Postmark measures 2.88″x1.09″ The Pictorial Postmark measures 2.73″x1.08″

Updated August 28th from the Postal Bulletin:

On October 6, 2020, in New Rochelle, NY, the United States Postal Service® will issue the Hanukkah stamp (Forever® priced at the First-Class Mail® rate) in one design, in a pressure-sensitive adhesive pane of 20 stamps (Item 574800). The stamp will go on sale nationwide October 6, 2020, and must not be sold or canceled before the first-day-of-issue.

This new stamp celebrates the joyous Jewish holiday of Hanukkah. The stamp art’s colorful digital illustration shows the lighting of the Hanukkah menorah — the nine-branched hanukiah — on the last evening of the holiday. All eight of the Hanukkah candles have been lit, and the child is reaching up to replace the shamash, the helper candle used to light the others in the menorah. Art director Ethel Kessler designed the stamp with original art by Jing Jing Tsong.

No automatic distribution to post offices.

How to Order the First-Day-of-Issue Postmark:
Customers have 120 days to obtain the first-day-of-issue postmark by mail. They may purchase new stamps at their local Post Office™ or at The Postal Store® website at usps.com/shop. 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:

FDOI – Hanukkah Stamp
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 February 6, 2021.

Technical Specifications:

Issue: Hanukkah Stamp
Item Number: 574800
Denomination & Type of Issue: First-Class Mail Forever
Format: Pane of 20 (1 design)
Series: N/A
Issue Date & City: October 6, 2020, New Rochelle, NY 10801
Art Director: Ethel Kessler, Bethesda, MD
Designer: Ethel Kessler, Bethesda, MD
Illustrator: Jing Jing Tsong, Kailua Kona, HI
Modeler: Joseph Sheeran
Manufacturing Process: Offset, Microprint
Printer: Ashton Potter (USA) Ltd. (APU)
Press Type: Muller A76
Stamps per Pane: 20
Print Quantity: 15,000,000 stamps
Paper Type: Nonphosphored Type III, Block Tag
Adhesive Type: Pressure-sensitive
Processed at: Ashton Potter (USA) Ltd. (APU)
Stamp Orientation: Horizontal
Image Area (w x h): 1.05 x 0.77 in./26.67 x 19.558 mm
Stamp Size (w x h): 1.19 x 0.91 in./30.226 x 23.114 mm
Full Pane Size (w x h): 5.76 x 5.8 in./146.304 x 147.32 mm
Colors: Black, Cyan, Magenta, Yellow, PMS 7405C Yellow
Plate Size: 320 stamps per revolution
Plate Number: “P” followed by five (5) single digits
Marginal Markings:
Front: Header: Hanukkah • Plate number in bottom 2 corners
Back: ©2019 USPS • USPS logo • Two barcodes (574800) • Promotional text • Plate position diagram (8)