Ubisoft has announced an upcoming rhythm title from a totally new IP, called Rocksmith . The game lets players strum through tunes by artists such as, David Bowie, Interpol, and The Rolling Stones using any real electric guitar they may have sitting around the house with a quarter-inch input jack.
http://www.joystiq.com/2011/03/15/ubisoft-announces-rocksmith-a-rhythm-game-that-uses-real-guitar/
I'm a guitar player myself and I'm all over this idea. I guess it will be hard for Ubisoft to market this, but if it's done well this could really cater to musicians that want an easy way of practicing songs and jam with friends online.
Can't wait!