The ANTCommandos PS2 to PS3 adapter I ordered a few days ago turned up while I was away on holiday. Did a quick test with it tonight with Guitar Hero 3 on the PS3… So far it works pretty much perfectly, there’s only two minor negative points:
1. The tilt needs an extra second or two to activate Star Power, the manual puts this down to a different type of sensor used in the old PS2 guitars (mechanical instead of accelerometer).
2. Holding down Start and Select on the guitar brings up the PS menu, this in itself isn’t a problem, in fact it would be a really handy feature except that you have no way of selecting left or right (up and down is done by strumming). E.g. if you go to “Quit game” when it asks “Are you sure?” you cannot select “Yes”.
Like I said these are really minor points and as this is just going to be used as a second player guitar there’s not really any issue.
As I don’t have Rock Band (yet) I can’t test that but it looks like it should work perfectly.