It's not commonly thought that the current console generation will be one with a little bit of a longer life cycle than the one before it (particularly in the Xbox's case), but typically that belief applies to the Microsoft and Sony systems. The Wii is sometimes excluded due to its already comparatively outdated hardware.
Yoichi Wada, CEO of Square Enix, believes that a new Wii will be released by 2011. Instead of having capabilities beyond the PS3 or Xbox 360, Wada believes that the new Wii will have features more in line with today's consoles but with the possibility of a new controller.
Read more at the Financial Times.