Really? It was one of the books kids who took a Sci Fi Writing class my senior year had to read and everyone told me it's awesome. In fact, they hated this movie just because it wasn't true at all to the novel.
As for me (haven't read the book), I'd agree that it was alright. It seemed that if I took the core of it, it would basically be 28 Days/Weeks Later, but less well done. Will Smith does a good job with what he has, but the script is pretty bad.