This needs several things to be topped. It needs Nolan and pretty much every crew member involved with The Dark Knight. It needs Nolan to be 100% totally committed to it, if he comes back for just cash (which I'm doubtful he would) then I won't be as enthused. He needs to add top notch casting in addition to Bale and Co. He needs to ignore fans and studio execs requests to 'do this' or 'add this villain'. Most importantly, and this may sound strange, but I think he has to look at The Dark Knight as an average movie. Pretty much, Nolan has to believe he can deliver something even better than The Dark Knight. Can it be done? Not sure, it's a tough ask for anyone, striking gold once is hard, twice is rare, three times is almost unheard of.