i don't exactly know what you mean, but as far as what comes with it...

There is a new drum system that has symbols as well as drum pads.
As far as I know they are a rubber material and don't make as much noise as Rock Band.

There is a microphone very similar to RB, but the singing is slightly different in terms of how it catches your pitch.

Some modifications have been made to the guitar as well. Along with the five color coordinated buttons there is a slider pad for tapping. This will allow you to get those tricky solo patterns without strumming. It takes the place of the strummer.

As far as song choice goes, they tried to listen to the fans as to what they really wanted to see on the game.

You can get more info on the G4 podcast for X-play. They did a GH:WT special a couple days ago.