I always liked the fact that the Penguin hits close to home for both Bruce and Batman. If he were in the next one, I'd like to see him come into Gotham as a savior, using his wealth to help rebuild the city after the terror they just went through with the Joker. Kinda the same route as Returns, but no mayor angle. Just a wealthy entrepenuer who seems as though hes trying to do what Bruce is doing, helping those who can't really help themselves. He'd be in all the same ritzy circles as Bruce, which would make for an interesting confrontation when Batman finally learns Cobblepot is really the Penguin. As for the whole Penguin aspect, while he's helping save Gotham, hes setting himself up as the premiere crime lord, not just of the mobs, but of all Gotham, running everything, and using the cash ammased from his illegal enterprise to further his criminal gains, as well as getting a one up in the public eye. I really think the people of Gotham should love the Penguin until he's revealed, another golden boy like Wayne. And as far as attire goes, give him a tux, hat, maybe an umbrella here and there, I really think the Penguin could work.