watched the DVR of this late last night when up with the new baby; Meh, I'm casually interested. Will watch again next week, but my initial thoughts hold steady for now. I don't think this show has the staying power in its plot unless it goes whacko-stupid-alien-gayness. And if it does, I think a lot of viewers will drop like flies. The main population simply doesn't like sci-fi.
IMO, I think you'll see this show bleed viewers as they drag out the plot, and it'll settle in around 7 million. For NBC, that would probably be enough for a second season.