The internet is very very mixed on this trailer.
There seem to be a lot of Prometheus fans upset that they didn't get a direct sequel, and as many Alien fans are upset that it feels like a slasher movie. You've got the people who really want the Blommkamp thing to happen (even though it will anyway). A ton of people disappointed with Prometheus are writing it off because they don't want to be "fooled" again. People sick of reboots are decrying it. Reddit doesn't know what to think, Facebook seems nonplussed, 4chan loathes it. Some people are saying it even looks fake and cheap, which is insane.
I personally loved the trailer but the whole reaction has just put a damper on my hype.