I was at an incredible presentation at the Game Education Summit this morning, by a professor of religion. She's working on a game to teach the Tibetan Book of the Dead in Second Life. I hadn't known what was possible in Second Life, and now I'm wondering who's working on teaching classics there: I'd love to move towards some kind of collaboration on some immersive learning.
You might also be interested in the Trondheim conference on gaming and Classics which was held this past February; the proceedings will be published in book form and online in early 2010. Here's the site (not a good one, I'm afraid, but more content is forthcoming: http://classicscomputers.wordpress.com/.
Lastly, there was the Re:LIVE 08 Conference hosted by the Open University in Milton Keynes which focused solely on MMOs and virtual worlds as virtual learning environments. You can read about that conference here: http://www.open.ac.uk/relive08/.
There is some primitive machinima both here on eClassics and on YouTube from the Re:Live conference -- we held a virtual conventiculum featuring students from three countries (Sweden, America, England), speaking Latin in real-time. Voice in Second Life was pretty awful, so I am playing with Skype or Vent, running the audio outside of SL.