Hey, turns out we missed a Tim Schafer interview on Gamespot, and I thought it was worth mentioning anyway because of how good it is. Read Tim's thoughts on Psychonauts on Steam, digital distribution, and, briefly, the new game. He doesn't mention it being multiplayer, but it totally is.
Update by Gabez: Also on the subject of slightly late news: Psychonauts gets on a list for the best games you've probably never played before. :~