Game Informer, along with several other gaming news sites, are reporting that Nintendo is preparing to unveil a successor to Wii at E3.
Not much on specifics, but the thing will be capable of 1920x1080 Progressive over HDMI (About Damn Time, Nintendo). Also, it is rumored to pack more horsepower than the PS3. Whehter or not that is the Wii vs Xbox 1 level or if it is Gamecube VS PS1 level, is unknown.
Nintendo is also rumored to want to regain the hardcore gaming crown it lost after the SNES days. A reminder to Iwata-San and Reggie: Animal Crossing won't cut it, let Retro Studios shine here.
It will also be backwards-compatible with Wii software (and likely GCN software by extension). This means Motion Control will return, and implies a late-model IBM Power-PC architecture.
Some sources indicate Nintendo may tease us a bit before E3.