Gary passed away in 2008 from an abdominal aortic aneurysm. His wife, Gail, has since spearheaded the Gygax Memorial Fund, set up to raise money to build a statue of Gary in Lake Geneva in memory of his contributions to the development of role-playing games. Amongst other fund-rasing efforts, the fun released the book Cheers Gary (currently out-of-print, but expected to be reprinted) at GenCon 2011, which compiled his many thousands of posts right here on EN World.
WotC will be donating a part of the profits from the upcoming limited re-release of the 1st Edition AD&D core rulebooks to the Gygax Memorial Fund (you can see the covers here).
I hope you'll take a moment today to remember Gary's contribution to the games we all play and love.