[quote name='chodax']Kinda OT but does any one know if the PS3 guitar will be compatible with GH1 and 2?[/QUOTE]
There's a thread here (do an advance search for "guitar hero" under the PS3 forum) that addresses this.
Not sure of the last posting but it said it is fully compatable with II and only partially compatable with I and 80's. Sounds odd to have a partially compatable controller.
Because of that, I'm waiting it out for a conclusive verdict on the final release. If the PS3 guitar works with I, II, 80's and Rock Band, then the PS3 version is a no brainer, IMO. If there are partial issues with any of them, I'll opt for the 360 version for achievements and online play.