According to sciencefiction.com “at his panel, when asked a rather snidely worded question about if he would do a sequel to ‘Dredd’ even if it was poorly written just for the money, Karl Urban revealed some very interesting information for fans.
Well, after he quipped that he did need a new house, he revealed the information:
Yes. ‘Dredd 2′ is in development.”
That’s literally the only information we have at present but fingers crossed we actually get to see it.