I dont think its going to happen too much in 2011, just because of the amount of money you would have to pay for a successful franchise to go single platform only. Someone in this thread mentioned something like GTA or Bioshock, if we said that the publishers would expect to sell at least a few million on each platform (under selling it here but keep with me), take that cost and we are talking ALOT of cash (50 million per game perhaps). So do i expect it to happen with a mega game. Nope. I think MS has learnt from the GTA experiment that, that money could have been better spent on a few studios.
Best bet are smaller publishers where you can finance their game for 5-10 million.
I think the way both Sony and MS have started to go, with game Extras, will be what they will do, Sony and its HD line and MS with the Dead Rising 2 prequel are examples of that. I expect to see lots more of this next year, and Sony will really push the HD line (They should pay Rockstar to do a HD version of GTA1,2,3 etc).
