The hype about Cloverfield is going crazy right now, and word on a sequel is high on the agenda, at least for the fans if not the film-makers. They are a bit more relaxed about it all and are waiting to see if there really can be another film made rather than just cashing in on the success.
J.J. Abrams and Bryan Burk, two of the producers of the film, have been talking about the possibility of a sequel and revealed that there's more backstory to all of this to be explored.
Perhaps we may see a prequel to Cloverfield rather than a sequel?
"...has fleshed out an entire backstory which, if we're lucky, we might get to explore in future films..."
So sequel or prequel, who knows at the moment, the real good news is that J.J. Abrams says quite clearly that he wouldn't want to rush into a Cloverfield sequel or prequel just because of the excitement around the first.
"I'd want to do something that is true to the spirit of what we made."
Now that surely is good news. No cashing in on the sequel/prequel at least. Personally I think it's more likely to go prequel as telling the same story from a different viewpoint can't really give as much as Abrams would want for a second film, surely. It's just the same story.