I just got back from Predators. For this who liked the others, particularly the first one, it is highly recommended. It is definitely in the same vein (haha) as the first one, with several nice references to it. Having a whole bunch of people who don't know each other, have completely different roles in life and personalities, and don't necessarily get along lends to more interesting character interaction a wider variety of fights. There are also a couple good twists at the end (all painfully obvious, but cool to see in action nonetheless).
My friends who aren't familiar with the predator movies found it fairly scary and had a lot of surprises. Me, having watched the predator movies a few dozen times each and having read practically all of the comics, there weren't much in the way of surprises but the action was still cool.