Well perhaps not as smart as chimpanzees - that article talks about chimpanzees as tool-makers, which is a huge deal when it comes to "intelligence". I don't really see Aliens as making tools; pressing buttons is one thing, constructing the button is something else entirely. My cat can work a door knob, but she certainly can't make one.
Of course, the problem here is we're comparing Aliens and humans, two species which have completely different physical abilities and social goals. One could argue that we'll never see Aliens making tools because they don't need to, and that we see them throwing their lives away in front of rapid-fire weapons because they've got different social priorities than humans do. Humans, as individuals, value their own mortality. Aliens probably don't.
