I agree everything after Jerusalem things slid down hill... a bit, but hardly felt it was horrible. There were still some good moments there, particularly with the Jewish chick, the zombie version of William Fichtner and Pitt enjoying a cool, refreshing, Pepsi after getting his "camouflage" from the zombies. Overall, it's a movie I liked. (Saw it again this past weekend with another friend who wanted to see it.)
Plenty of mis-steps in it (zombie apocalypse and two guys are going for a rape in the dairy aisle?!) but overall I enjoyed it.