The Wii ...
I don't really see the PS3 as having that long of a lifespan because in 2010/2011 Microsoft will release a follow up console for the XBox 360; the system will be able to match the per-pixel performance of what the PS3 can produce (when rendering at 480p @ 30fps) while being able to output at 1080p @60fps, will have a Blu-Ray player and will sell for $300. It will see enhanced ports of (pretty much) every PS3 game and will see the release of many/most of the PC games which the PS3 can not run. Ultimately, this system will eliminate all of the selling features the PS3 will have later in the generation.