The actor eventually chosen to be the new Batman will have to have a few attributes—they'll have to be at least somewhat physically imposing and be able to perform a physically demanding role (not only will there be a number of fight sequences, undoubtedly, but wearing the suit is a task in and of itself); they will have to be comfortable with signing on for a number of movies (sequels, spin-offs, whatever); they need leading-man presence and acting chops (presumably whoever plays Batman will have a lot less screen time to establish who this Batman is compared to the already established Superman). Moreover, they'll have to have some chemistry with Henry Cavill, while at the same not outshining him either. It's a daunting proposition, but that's not going to stop it being highly, highly coveted.
Even within that set of parameters the kind of actor they'll be looking for depends on the kind of Batman the writers are going for. Nolan's "The Dark Knight" series, after all, showed us that after many different kinds of Batman stories, there are always other ways to approach even the most established of characters. We've chosen five different potential kinds of Batman (seeing as we're not privy to the tack they're taking), and picked out a list of five actors who could fulfil the needs of that character if Snyder and Goyer actually go there.
One of the actors who could truly pull off Batman and is an equal to Superman Henry Cavill's—both in terms of handsomeness and rough age range, while not being so famous as to be priced out of the market—is Matt Bomer. For years Bomer has been turning in small, memorable roles in movies like "In Time" and (hilariously) last summer's "Magic Mike," while starring in cable TV series "White Collar," though mainstream stardom has eluded him. Playing Batman would certainly bring him stardom and then some, and besides having a really great chin (vital as it's the part of the face that remains on view when donning the iconic Batman garb) Bomer has a darkness that he rarely gets to tap into, as evidenced in that scene in "Magic Mike" when he prods Channing Tatum into fondling his wife's fake breasts. (He's also proven himself comedically too, should Warner Bros. want to incorporate some lightness into the character.) Bomer isn't a complete stranger to the DC Comics universe either; he voiced Superman in a direct-to-video animated feature earlier this year called "Superman: Unbound" and ironically, Brett Ratner wanted him for the lead role in the aborted, J.J. Abrams-penned Superman flick "Flyby" (read all about that right here). The only real downside is that Bomer's so damn pretty, he's not always threatening and he'd need to tap into some inner demons.
Odds They Go With This Kind Of Batman: It's a possibility, though Bomer would probably have to have a phenomenal screen test alongside Cavill for chemistry. And is it possible the two are too alike?
At the end of "The Dark Knight Rises," it was very clear that a new Dark Knight was rising in the form of Joseph Gordon-Levitt's character, a beat cop from Gotham named John Blake (real name: Robin John Blake). At the time, it seemed like that was the end of the franchise and Gordon-Levitt's role in it. In fact, that was the intention. There was never meant to be a sequel with Gordon-Levitt as Batman, and for fanboys hoping that would be the case, it's far too literal an interpretation of what Nolan and Goyer built. What Nolan was trying to say was Batman was a symbol and symbols are eternal and live on. Nolan was adamant about that symbolism (this being much more powerful than the physical incarnation of John Blake as Batman) and as a producer of "Man of Steel," it stands to reason the filmmaker would have argued the same going forward. But this is a new world now and Nolan's not really involved in "Batman & Superman" (or whatever this world's finest collaboration will actually be called) and will only take an executive producer credit, which means essentially very little active participation. So in many ways, WB and Snyder/Goyer are free of any Nolan rules in this new DC Universe. If they did go with Joseph Gordon-Levitt (which frankly, doesn't feel like it's going to happen, but it's fun to discuss), there's lot of potential DC Universe ramifications—effectively extending the Nolan Batman universe while simultaneously suggesting that both "Man of Steel" and those Batman movies exist in the same world (which takes a little logic leaping). The "cons" might ultimately outweigh the "pros" with casting Gordon-Levitt, whose physical stature suggests his Robin namesake more than Batman himself, and no matter how much Warner Bros. wants to quickly establish these franchises and this world (and this might be a shortcut to doing so), Nolan has long said his trilogy is closed and off-limits, so don't hold your breath.
Odds They Go With This Kind Of Batman: Sorry, not gonna happen.