Mark Wahlberg
Pros: Physicality is not a question with Wahlberg, if he isn't buff enough already to play the part he can get into shape anytime he likes with the sports complex he calls a home. The mans had an amazing physique for the past twenty years or so. Weve seen him play tough, mysterious leads before and his turns in movies like The Departed, Shooter and Max Payne show that he understands both the action side and dramatic aspect as well. He also has very expressive eyebrows and a good angry stare. He is a credible blockbuster lead, just the times he has found himself in them (Planet of the Apes) it hasn't worked out because of a bad production rather than anything he did.
Cons: Two words: Marky Mark. Wahlbergs past as an underwear model and rapper along with his past comedic roles might shatter his credibility as Batman, but Michael Keaton came from a primarily comedic background as well when he was cast and many think hell go down as the best Batman, ever. It may need to go in a more action orientated direction but Wahlberg could do this.