I kind of suspected aliens after seeing the trailer because they showed them opening the crate that said "Roswell, NM" on it...so I wasn't really surprised by that. (also, they open that crate at the beginning of the movie, too...so you kind of know it's aliens right from the get-go...kind of a spoilerage there..) Aliens weren't really fitting, but didn't bother me. I thought the movie itself was pretty awesome...but I haven't seen the originals in so long I barely remember them. I need to track them down.
I think the ending and killing of the bad guy character (Blanchett) could've been done better because I was confused on whether she died or just teleported to their ship.