Here's my problem with the show. It was advertised as a Mini-Series (finite number of episodes with a definitive conclusion) and the promos stated "by the end of Summer all the answers will be known" or something like that. Not true. NBC in calling it a "mini-series" was using a very liberal definition of the word. It was the first 13 episodes of a show that was left open-ended in case it got picked up. I'm pissed by how it ended because I expected, from what I'd seen in the ads, that it would be a self-contained show and that all my questions would be answered. Sure, I can make a decent guess at what happened to everyone, and possibly even to what's going on, but I don't know why (other than the mysterious group wanted it to happen). What was the point of it? See, that's a question, a major one, that does not get answered.
Had they been honest from the beginning ("here's a show that concludes it's initial story arc while setting up the next chapter of which you will never see because we aren't renewing it") or simply not advertised it as a Mini-Series where all would be answered, I would have been fine with it. I thought it had a strong ending that was well done and quite intriguing. Too bad the show was misrepresented by NBC (not to mention the sudden timeslot change one day, the move to Saturday nights, and not airing the 3rd last episode). You know, one should not have to work that hard to watch a TV show, especially in Summer.
Think maybe I misinterpreted NBC's promos? Judge for yourself:
http://www.youtube.com/watch?v=WWajphSnFtU&feature=related