I'm no sure if this is true for other systems. But the rb2 kit for the 360 will be compatible with guitar hero would tour / rock revolution coming out soon. So you wont need 3 set of guitar, drums.. So all you need to buy is the game..
Yes, for the 360 (cause tahts what I have) All peripherals for RB2 and GT:WT and RR (This game is a joke not getting it) are cross compatible with each other. So for me, I'm getting the GH:WT bundle and only getting the RB2 game.
Is there a difference between the rb2 and the GT:WT peripherals, that your are deciding to wait for the GT:WT peripherals
Rock Band guitars are fail. I'm a guitar player so a good guitar is the reason why. GH:WT's guitar is, from what I've read, the best guitar made for a video game yet. I couldn't care for the drums, I'd like to see how the 3 pad 2 cymbals work vs Rock Band's 4 pad drums.
They are compatible with each other. I'd suggest just getting GH WT and buying the rock band 2 disk. Or do what I did and rent the RB 2 and just put in your old RB 1 disk in there. xD I did that with halo and they never found out.