This stamp was announced by the USPS on March 6th:
One of the most influential public intellectuals in modern U.S. history, William F. Buckley Jr. (1925–2008) defined the conservative movement of the mid-20th century and was one of its most recognizable spokesmen. Author of more than 50 books, Buckley foundedNational Review, one of the nation’s leading conservative publications, and hosted the Emmy Award–winning public affairs television program Firing Line for more than 30 years. Original art by Dale Stephanos features a portrait of Buckley, created by hand with graphite and charcoal on hot-press watercolor paper, then refined digitally. Greg Breeding, an art director for USPS, designed the stamp.
No date of issuance or city was given. The latest information will appear below the line, with the most recent at the top.