Just got through watching 28 Weeks Later.
I did like the original movie 28 Days Later, to an extent. I thought the first half was great -- and then hated the part once they reached the base and it turned into some other "save the girl flick". I thought it got cliche and predictable, by then and that the film lost some focus on the whole "survival" aspect the film was had going on from the jump-start.
I'll take 28 Weeks Later over the original. This sequel kept me on the edge, wondering what the heck was going to happen next, at all costs -- even by the end, I was not sure how the hell most of these characters, in a horror film that made you care about nearly every one of them, were going to turn out. Most of these type of horror films, you'll wind up caring for namely the main characters that happen to be there in a movie with an ensemble-sized card -- and well, not too much more than that, unfortunately; which is a big mistake for many of these films (Wrong Turn, anyone?).
Since 28 Weeks Later revolves around the virus basically trying to tear apart at an entire family and spending time developing that story and depth before eventually all hell breaks loose, you do care -- it's just the world being decimated just so happens to be there, as another part of the story. It's always this family and those helping the family, getting the center stage.
Ending Spoilers
And well, my only complaint with this flick here -- the ending after what should be the film's ending.
The last minute ain't gonna murder what was other-wise was...
...A very good film. And probably the best "serious" zombie movie I've seen since the recent remake of Dawn of the Dead.