Fox Atomic decided to torture us by inviting us over the the swanky Fox lot to view the first 28 minutes of the in-progress flick, 28 Weeks Later (we parked in "The Sound of Music," and let me tell you ... those hills were most definitely not alive. They didn't have eyes either, thankfully). I can say with absolute conviction, if you liked the first one, you're going to like this one as well. It's also safe to say (according to Fox Atomic) that you don't have to have seen the first film in order to enjoy this one. That's definitely true from what I was treated to.
Here's the setting: it's 28 weeks since the outbreak of the Rage infection that decimated London in the first film, 28 Days Later (hence 28 Weeks Later ... both movies are timed from the infection outbreak, which is day zero.) If you haven't seen the first film, the Rage virus/infection isn't pretty. One bite (or even a single drop of blood) from someone who is infected will put you instantly into a "state of irreversible hyperactivity and murderousness," according to Wikipedia. It's almost like being turned into a familiar horror movie staple (we aren't using the zed word here), except with the extreme hyperactivity.