Here are the links that Gus mentioned during her presentation:
Quest Atlantis, an educational MMORPG produced on an NSF grant at the U. of Indiana.
Revolution, a historical roleplaying mod using the Neverwinter Nights engine, produced at MIT.
More on Revolution.
Hephaestus, a massively multiplayer online sim on the XBox, engineering robots to accomplish things in the world; elementary physics.
A central blog for academic discussion of the implications of video games.
Habbo Hotel, a European multiplayer environment for kids
Linden Labs, makers of Second Life, a non-quest driven MMORPG
Blizzard, makers of Warcraft
James Paul Gee's book, "What Video Games Have to Teach Us About Learning and Literacy"