while the timing may suggest a new console, I don't see it yet. I wouldn't doubt that Nintendo is working on a new console, but I think it's launch will be determined by the competition. Right now, the wii is doing just fine for them. They've just released the 3ds. I don't think Nintendo needs to risk a new console until either Microsoft or Sony announce a new system. Nintendo is happy just soaking up profits on it's less powered wii.
I don't think Nintendo will go the high power route. They make money without the risk of an expensive, high powered machine. Sony and Microsoft lose money on system sales, Nintendo does not. The wii proved, they could lead the market with less under the hood. I'd look at Nintendo coming up with the next gimmick or next innovation in gaming. That's not to say they couldn't be working on a high powered system, but I just don't see the motivation for them, seeing as they are perfectly happy and profitable with their current business model.