It's not crazy, but I do think it's too early. They can throw around ideas all they want, but they should really also wait and see how this gen plays out a little, especially as how there seems to be two schools of thinking on how a console should be.
There's the Sony/MS school of thought: More power and better graphics = teh win. They also favor multi-purpose consoles.
Then there's the Nintendo school of thought: Sacrifice power and graphics for control and gameplay, and have the console be mostly about games.
Most people consider Nintendo the wild-card, but honestly, why would Sony have put tilt motion into the PS3 controller if they didn't think Nintendo was on to something?
This generation is going to be very interesting.