I Am Legend Prequel Is Now A Sequel?

According to a scooper at AICN, the I Am Legend prequel might no longer be a prequel. The original idea was for the film to take place "several years before the original film" and follow Will Smith's character Robert Neville as he fails to save a small pocket of survivors. I'll admit, I was never a huge fan of the prequel idea, because we know where it will eventually end up. But Warner Bros was insistent in making the movie with Will Smith, and that was the idea he developed. But now rumor has it that the film will be a direct follow-up to the original film. Problem is, [possible spoiler alert] Smith's character is killed at the end of the first film. So how would this be possible?