I have to agree. While it certainly makes sense for him to have the ragged suit for his origin tale, it's equally sensible for Two-Face to eventually have the split suit. One simply can't make the same argument for Two-Face perpetually wearing the single, damaged suit as one would for the Joker living in his costume. The Joker in TDK seems to be largely a product of his own madness, sans the scar (though it's being frequently hypothesized thus far that only a single side of his mouth was probably scarred, and that he likely completed the other side to match and finalize his "smile"), and with that in mind, his outfit is in that same vein. He's creating his persona, building it from the ground up, that includes applying the make-up, dying the hair, and creating his own suit, which is an extension of himself in its twisted, hodge-podge zoot suit bastardization, mirroring the chaos within him and that which he looks to spread throughout society itself in violent anarchy.
Two-Face, though, doesn't look the way he does by choice. One would think that having been one of the foremost crusaders for justice in Gotham, as well as one of the city's most handsome and dapper, that he would want to shed remnants of the tragic event which transformed him. While his appearance is altered, Harvey Two-Face will also likely crusade for justice as Harvey Dent did, though albeit in a drastically different (and more violent) manner. Trying to establish himself as a figure to be feared, I think Two-Face would retain some of that dapper element, and look to wear a classy outfit as opposed to tattered rags. The damaged suit is awesome for an intro look, but in the long-run it doesn't make much sense (unless Nolan can sort something out... he's done pretty well thus far
). Just some thoughts.