At this early stage (hopefully Daniel Craig will do 2-3 more) I can see only two real candidates:
and Tom Hardy
Both are credible in different ways. Hardy seems to have more in common with Craig - diverse roles, 'serious' actor, untypical Bond looks. Cavill has a track record with Eon, has a following in America, and has the classic Bond look.
My feeling is that Cavill is the more likely of the two. I feel that Eon will go back to the classic Bond look after Craig. However, I would be happy with either of these two come 2015 or so.
Hardy has a problem as my Wife pointed out his looks, if people had a problem with DC then hell that will be a walk in the park compared to convincing anyone that Hardy is handsome.
I concur that he is not the "classically handsome" type. In fact in Wuthering Heights with long hair, he reminded me of The Kurgan from Highlander But then again 'Heights' showed his potential for the romantic/brooding side of Bond.
But Craig has opened the door for shall we say, slightly off-kilter looking actors to be considered. I think once Bronson hits the USA followed by next year's Warrior where he plays a MMA fighter, he'll be getting more support.
The thing about that Cavill picture above is that he seems to be unsubtly posing in a Bond-like fashion. The choice would be adequate, but I can't see that he'd bring any particular spark to the role. I wonder if its this reason that he gets into the auditions for so many superhero roles but never actually wins any. He'd look the part, but, I get a Brosnan Jr. kind of vibe.
I'm not a woman but my Wife say a big no no to Hardy looks wise!