Sadly, this doesn't sound like it's going to be a useful substitute on the PS3.
Not only does it not support wireless communication, but controller vibration, motion sensing, and the Playstation button don't work. So at the very least you're going to have to keep a second controller hooked up when you need to hit the PS button (Although Share/Options at least does substitute for Start/Select on a PS3 controller). And compatibility is only partial and several major games like Gran Turismo 5 and Grand Theft Auto V don't work with it.
Assuming that issues can't be resolved with a PS3 firmware update, hopefully Sony at least releases a PS3 version of this sans the touch pad since it seems to be a genuine step forward at long last for a Playstation gamepad. I can't imagine anyone eschewing buying a PS4 just because their PS3 could use a similar controller and I'm sure that a lot of PS3 fans would gladly buy a PS4 lookalike.
So it would only be a positive where Sony's business was concerned.