Twilight princess will be playable on the revolution wether or not this is true, The revolution is designed to run both Gamecube games and revolution games, So, if Twilight Princess is a gamecube game, it will work on the revolution and gamecube, if it is a revolution game, it will just work on the revolution.
The image below is what Joystiq actually had scanned on their frontpage:
It's not actually been confirmed either. It states that he'd like to see something like that.
We also have comments from Engadget the state the following:
Speaking of GameCube, if you play a GameCube game on the new Revolution console, will you be able to use the Revolution controller or will you have to use the older style of controller?
Well, all of the GameCube games will be compatible only with GameCube accessories, so whether itís a WaveBird or whether itís a wired controller, youíll only be able to play those titles with those accessories. Essentially what weíre saying is that Revolution titles are the only ones that will leverage the new controller.
If you look at the additional bolded bit, you'll see that it says that only new titles will use the new controller, and unless what he said in EGM constitutes as a Revolution title, we're not getting additional controller abilities - at this moment in time. Who knows what's said in the future.