i am sure that there will be games, sold via itunes. apple wouldnt miss out on this opportunity, and with touch screen, should be interesting to see what brilliant control methods they come up with.
There's obviously some serious game development going on the on iPhone & iPod Touch platform, especially from the Indie side compare to current game companies that are simply porting old stuff that they got instead of building from scratch for the platform...
Checkout SIO2 Interactive and the SIO2 engine technology, there's a huge community of indie game developer based around it.