To be honest, I find it a little depressing that people actually have preferences based solely on whether the candidate is a 'nice English chap'.
On Cameron, I don't trust him. I've heard him described as 'Blair in a blue suit' and that sounds pretty accurate for me. He's only now being looked on favourably because he's had the good fortune to stand opposite a lethargic and deeply unpopular government.
Cameron does, however, have some good people around him in the shadow cabinet (Hague being a good example) so they do have that plus. So I guess it would all depend on Cameron's leadership style.
Next election is really a selection between two bad candidates (I'd say Brown is better-intentioned than Cameron but it's kind of outweighed by his weak govt and his inability to rise to the premiership).