I thought this was great, fun film. Had low expectations for the film (like most people probably). I think the negative hype is what killed the film plus the first Judge Dredd film. They should definitely do a sequel for the same reason Batman Begins got a sequel even though it didn't do as well as people were hoping.
Anyway, I have to agree with James opinion on Lena Headey's character. For the first half of the film she's shown off as being this bad ass
but the movie ends with her basically doing nothing much really except talk. They should have had her be more of a fighter. Perhaps the drugs make her go crazy like someone on PCP or something.