To be honest, I wouldn't be upset if games never get better looking than they are now. I don't mind it either way, but this new console technological capacity only means a combination of substantially bigger production costs for developers, in order to make a game that will take a substantially longer time to develop, and cost the consumer more money. I'll also mention that as technology gets better, it becomes harder for a wannabe game designer to "learn the trade" and get to the point where he can develop a game that has the potential to be commercially successful (read: less opportunity for young development teams with fresh ideas to get into the biz)
I couldn't care less whether the Revolution is any more powerful than the current Xbox; I'm content with the visual aspect of the current generation games. My only concern is with whether those games are fun or not, and I feel Nintendo surpasses its competitors in bringing new ideas into the mix to try to make a better gaming experience for the player.