I saw this movie on Friday night... Must say it is way more intense than the 1st one, and owns Land of the dead. I'd probably put it even with Dawn of the dead for zombie movies.
Recently they have seemed to be changing the definition of a zombie from slow moving stupid creatures to the capabilities of humans or greater.
The first 15 minutes are pretty intense followed by a 30 minute lull and then the final hour or so is great. It probably could have been more graphic in parts and the camera could have been more focused but all in all it was just an intense movie.
They set it up where a 3rd would be possible.