Ok, got a small info from my friend:
- Engine is nearly 1:1 from PS3 version
- They added a few new gimmicks to the engine, so they can utilize more PS Vita
- Game is gorgeous, clear and crispy textures, big draw distances
- Character models are awesome, the same with animation
- Stable FPS even with gigantic action inside levels
- Literally - game is like portable Killzone 3, looking better than Uncharted.
And yes, we've got new protagonists, release date and many other thing, but.. I cannot speak about them right now. There's a lot of goodness, believe (I just read whole preview), I'm excited as hell.