My knowledge on Penguin isn't as extensive as others, but I do know a good deal about him to vouch for the character. I think he's interesting, I like the complex that he has, I like his intelligence, and he has a much less menacing appearance than a lot of people in Batman's rogue's gallery that sort of adds to the element of surprise. All of this would work fine in a Batman movie. I wouldn't mind seeing the Penguin, but in all honesty, I much prefer Black Mask. Whether Bruce Wayne will know it or not, he would have to contend with(I know this has probably been brought up a dozen times) Roman and his alter ego. And this has been offered throughout these boards because this concept IS a good and interesting concept, and this is something Batman in the Nolan series has never encountered.
Each villain has pushed Batman to a level he had never encountered. For BB, it was obviously fear, facing his own, facing Gotham's, and also he was facing an enemy who "knew" better than any other villain. Who knew his identity, who had the skills to challenge Batman physically. In TDK he had to face the unpredictability of the Joker, his madness, and his influence on Gotham and its white knight, "Two Face." If the rumors are true, then Batman will be dueling with his morals via Catwoman, will be pushed to the brink of his intelligence, Riddler, but nothing has really CHALLENGED his family name, his business. Roman can fit PERFECTLY with this, in ways the Penguin absolutely can't.
Yes, it's probably the same old reasoning for putting him in the movie, but it's a damn good one. And also add Black Mask running the mob, or somehow developing his false face society, with Batman on the run and his family legacy being endangered, is compelling IMHO. I can't really see Penguin pulling this off and representing the kind of dangers BM can. To each his own I guess. I gotta' start posting here more often, geez.