It's out on 360, not sure about PSN or PC (I think the game's coming to PC).
I didn't like it that much though. It was alright, just nothing amazing. ok graphics, ok controls. The flight controls feel sort of loose. The on-foot shooting feels a little weak. I melee'd a guy and it gave me a canned animation from a preset camera angle, which took a few seconds. Then it gave me control back. It almost felt like a mini cutscene, and it sort of took me out of the action in a way I didn't care for.
I was considering getting this on release, but I think I'm gonna just wait for a price drop, especially with so much else coming out soon.