I doubt the Revolution will be a graphical monster, I think it will be technically weaker than the Xbox 360 in many aspects. _But_, we've all seen what the "weak" Gamecube can do if we look at Resident Evil 4, the graphics in that one is awesome. So I think it very much depends on the developer how well they optimize the games and stuff.
One more thing, Nintendo have theyself said that they aim the console to the major public, so I think they want to push the price as much as they can.