Today, the gaming community mourns the loss of one of the true legends and pillars of the industry.
E. Gary Gygax, co-creator of the Dungeons and Dragons pen-and-paper Role Playing Game, the thing that started the RPG revolution (both traditional and online) has passed away March 4, 2008. Mr. Gygax passed away peacefully at his home. He was 69 years old.
There is a current obituary at the D&D site.

I had the pleasure of chatting and meeting Gary at the 1997 GenCon. I will try to find that old photo and post it soon. He was a good man and my idol. He even signed my original D&D Player’s Handbook.
You will be missed, sir.
Thank you for starting something that is only limited by our imaginations.
UPDATED (Mar 8, 2008): Some related tributes and links