No Hannah Montana on Rock Band, I suspect...

And here's why.
Which is kind of a shame, as I know that lots of younger kids really enjoy Rock Band (and Guitar Hero, for that matter). The idea of a tween-centric Rock Band would be a great way to get more kids to force their parents to plunk down $170 for the guitar/drums/microphone set so they can thrash about to their favorite High School Musical tunes.
Alas - it looks like Disney is going to go their own way. (Why no Fleetwood Mac on Rock Band!?)