E. Gary Gygax, co-creator of Dungeons & Dragons, passed away on March 4 at the age of 69 at his home in Wisconsin. Gygax was at least partly responsible for making the Platonic solids cool, in particular the icosahedron (d20). Order of the Stick has a nice tribute to Gygax, as does Penny Arcade. We nerds of the world will miss him.
Update (3/7): xkcd has a tribute up now.