About a month ago Dhani Harrison said that he was working on Rock Band 3 to make the game a more realistic experience, but Harmonix says you shouldn’t listen to him.
John Drake of Hamonix said that Harrison was “speculating wildly” and that he is not involved in the development of Rock Band 3.
I’m gonna say it is more then likely that Harmonix is trying to cover up their tracks since it seemed like Harrison was pretty clear on the fact that he was working with them. But who knows, maybe plans have changed. We will just have to wait until Rock Band 3 is officially announced.