I dont think microsoft should make any download only games because most people just arent ready for that.
But i do think microsoft should start releasing game for games on demand at the same time as they release at retail.
End of 2012 prediction:
xbox 360 : 73-75 million playstation 3 : 72-74 million wii : 104-105 million
Most hyped for :
Bioshock: infinte, The Last Of Us, Alan Wake's American Nightmare and Agent