Quite liked it so far. Thought it was very heavily influenced by Lost (out of time sequencing, plane crash, but hey, since when was Lost a total failure?) There was a bit of 24 in there as well (black president, whats the obsession with that all of a sudden? I mean I get Obama and stuff, but really? Every president now is black? Whats that about?)
I did suspect aliens quite early on though, when the CIA guy was talking to the President in the oval office and he had the file on them, I thought it might be aliens and then they almost went out of their way to avoid calling them "people" until the reveal. But again, so what?
The wife lost interest when the aliens were revealed, she hates sci-fi, but I was pretty much engrossed the whole way through the first two episode and I'm looking forward to more. Some of it was a bit laughable - e.g the bloke in hospital, supposedly a murderer just gets up and dressed and walks out of his room with no one noticing. Agree with the other poster, the chase scenes were a bit overdone.
I'm fully expecting this to not get a second season, due to its similarities to Flash Forward, but fingers crossed. I'm happy to know I'll get to enjoy at least one full season.