No offense, but I love how averyone assumes they are referring to flagship games like Madden. You do know EA produces games like Dead Space and Mirrors Edge too, right?
And I have been reading quite a few articles recently talking about the SPU's in the PS3. Apparently most, if not all, developers have just begun to scratch the surface on how to 'farm' all of the computations out to the many SPU's on the PS3. Towards the end of the life cycle games are going to look ridiculous. Even a lead guy from Valve, a company whom I thought previously said that they hated the architecture of the PS3, said that the capabilities of the PS3's SPU's is enormous.
With that said I know many gaming 'experts' have said that games probably aren't going to be able to look much better than they do this generation. As far as graphics go we've reached the peak. The next generatiohn of consoles will probably show a negligible difference in graphics but it will be more about advancements in AI and such.