I found this to be an immensely enjoyable horror film. While it's not the be all end all of horror films, it's exactly what I wanted. I'm actually not a fan of Whedon but found this to be a perfect blend of satire, comedy and horror. The scares and creepy moments are well earned and the performances are all really good. Fran Kranz steals the show and Bradley Whitford is great as is Richard Jenkins.
A lot of people have been saying the CGI is awful and that the ending isn't explained.... it's explained enough that it made sense to me. I hate that people need a definitive explanation spelled out all the time. I personally love the classics where there isn't a neat tidy ending. In the original Halloween we have no idea why Michael is the way he is and why he's unstoppable. All we need to know is that's the way he is and it works.
Now, the CGI was a little shoddy in certain parts but I can't help but think that that's what they were going for.... I dug all the references (And there were alot!!)
Overall, awesome movie. Horror fans who bitch about a lack of originality owe it to themselves to see this at least once on the big screen. And I really want that damn bong.......