I'm not too thrilled with what I see in the trailer. Especially since they haven't learned from the mistake of #1 and set it on modern-day Earth
AGAIN. That only works for Predator movies, not crossovers.
I am not pleased by civilians being offed on-screen. It's tasteless. Yeah, the whole colony in Aliens went "pfft," but it was almost completely off-screen, and we didn't have this shit of trying to excite sympathy for people only to have them go splat. It's a cheap ploy to try and tug at your heartstrings. Aliens did it much better: they go splat, then you find out what happened and feel sympathetic.
I like some of the concepts (double shoulder cannons, whip, the double impalement, chick being stupid enough to try to fight in an undershirt and short shorts getting offed), but as a whole, it seems mediocre (still better than #1, though), and an exercise in gore porn.
However, I'll link to the trailer here:
http://media.movies.ign.com/media/746/746237/vid_2097673.html