as far as sequels go- my thoughts:
bane as the main villain (played by javier bardem), with riddler in a smaller role (played by joshua harto, "mr. reese"- mysteries)
have bane's origin be similar to the comic- he's finishing his father's murder sentence in jail, as his father died, and this weird south american country he lives in does things this way. he hears of this unstoppable force in gotham- batman- and makes it his life mission to defeat him- just to say he did, that he is the greatest, and to seize control of gotham from batman- this guy wants power. eventually he gets out of jail (end of sentence or breaking out... whatever)- he travels to gotham, and establishes himself as a big drug cartel lord (who conducts his drug business in his trademark mask) with his own brand of drug- a ridiculous rage 'roid that pumps up your adrenaline, making you stronger, faster, etc.- a valuable tool against batman, who is rendered a bit ineffective due to the cops being on his tail all the time. (through the movie, he would have lucius develop a sedative for this particular drug). using the money he makes from here, he begins buying up businesses especially those in competition with wayne enterprises, which is the biggest company (presumably) in the world, just so that he can say he beat out wayne enterprises (this man is driven to beat the best- physically, economically, mentally, etc.)-
all this leading to his establishing himself as a "legit" businessman in gotham.
meanwhile, mr. reese is held in police custody as an "accomplice" to batman (as he supposedly knows his identity). they are trying to get batman's identity out of him (as batman is on the run), but he refuses to give it up- batman (well, bruce) DID save his life... and he feels a bit of a life debt to batman. plus, he wants a crap ton of money.
gordon is conflicted throughout with having to hunt down his former ally, all the while having to deal with this new drug epidemic.
bane ends up making reese's bail (wayne doesn't, as he does not want to appear overly suspicious)... he hears this guy knows who batman is, and he wants to know. he initially employs reese, and then one night, at a business party, he gives reese a taste of the drug (which is highly addictive)- reese ends up being hooked, finally feeling powerful, and eventually, after reese is really addicted, bane withholds the drug from him, demanding the info of batman's identity. reese ends up giving it up of course, being the junkie he is- but of course, bane has to use a little physical persuasion, exerting his dominance.
thus begins bane's personal war against wayne and batman, setting his customers (re: adrenaline-enhanced junkies, who amount to a good number of the citizenry- a quarter perhaps?) on batman (as a spin on the breaking out of villains to wear batman down) before finally confronting him himself. i would like to think that, during all this fighting batman has to go through, he contacts lucius, asking him to contact reese and get him to do some espionage into his employer's (bane's) activities, dealings, etc. with promise for help with his addiction. this info would help batman to defeat bane. thus reese, or the riddler, is a bit of an anti-hero- a druggy who ultimately helps batman (this anti-hero angle reflects a bit on riddler's current status in the comics).
of course, id like to think also that there would be plenty of bruce and batman- bruce in the business end, and batman fighting against cops and junkies alike. it would end with reese, now recovered from his addiction, appearing on engle's show claiming to reveal the "truth" behind batman... but in fact revealing that the crimes batman has been condemned for are in truth the crimes of harvey dent (a truth he has pieced together), and that batman took the fall for it, and that batman was the one who took the city off the grip of bane's drugs, and provided the means to get off the addiction (the "antidote" thing lucius had been developing thru the movie)- revealing, in effect, that batman is gotham's true defender, and one the city can put faith in. harvey dent, however, was not evil, but was rather driven to madness by the loss of his loved ones and by the joker's influence (though this leaves a hole- what of the criminals Dent put away? unless of course bane bought them out of jail, and now they are in jail again for completely different crimes- drug addiction and conspiracy against the state with bane- and so their original sentence is inconsequential). as for the identity of batman- that is one riddle he will not give up.
thats my two cents anyways.