Thought it was mighty fine. Always fun to see aliens that look and act alien. And once again, the only real monsters are the home grown variety. It'll be fun to see how widely the Academy ignores it come nomination time, except for one or two token technical nominations. Oh, that's right, there'll be room this year for it in Best Picture, etc...that way everyone can feel good that they included it in the nomination when they vote for something most people haven't seen and probably never will for the win.
As for the 'open' ending...well, a sequel wouldn't necessarily be the end of the world. Or would it?
8/10