I think the jump will be more subtle at first especially as developers are so used to focusing on games PS3 and Xbox360 can do. Give it a couple of years and you will see how much greater scope developers will have found to develope games.
The new consoles can't really do new gameplay. Just better graphics and even then, the jump is pretty small. Most people don't notice much of a difference between a PS3/360 game an a maxed out PC game. Only when a direct comparison is done.
Read the mania: http://www.fanfiction.net/~nonexistinghero In SA2, it's Super Sonic and Hyper Shadow.
This has been the worst gen for video games possibly ever. If the major drop off in quality in modern video games is any indication, then we're in for the worst of the worst video games of all time. I am definitely not looking forward to another disappointing mediocre gen.