102 button guitar. Jesus Christ.
Right now, they have to sell me on the Pro mode. I'm willing to shell out the money for yet another "real" guitar, but the game has to actually be a good instructional tool for it to be useful in any way.
I feel bad for all those Ion Drum Kit people though. Their 300 dollar kits are now useless.
Some more details:
For peeps who like drums, it seems that they've been adding cymbal support into ALL previous RB2 DLC. It looks like none of the old songs will be compatible with Keyboard or Guitar Pro though.
A couple of videos showing the madness that is pro mode.