recreate the entire World of Warcraft inside the indie sandbox hit, Minecraft. And as you can see above, he's doing pretty well -- the entire continent of Kalimdor (including the new zones from the Cataclysm expansion) is almost done, and he's well on his way to doing the rest, including all of the instances and dungeons.
Rumsey came up with some custom software to put it all together, which basically translates the current maps of WoW over to the measurements of Minecraft blocks. Rumsey is trying to keep Minecraft's "1 yard to 1 block" ratio, though that means he has to balance WoW's detail with Minecraft's inherent blockiness (and Minecraft's height limit of 128 blocks has required mods to make some of WoW's tallest features work). Still, what's been created so far is certainly recognizable as Azeroth.
Now if we can only get StarCraft, Crafting Mama, CrimeCraft, GemCraft, and macaroni and cheese in this project somehow.