I was a bit pissed at Bisping too after the Hamill fight, but after six months or so I slowly started to cool down.
It would be fun i Bisping won just to piss of all the forum members who still think he's worse than Hitler. He was disrespectful that one time over a year ago, get over it.
With that said, I think it will be a battle. Leben has improved tremendously since TUF, both mentally and physically, and he will be a much bigger challenge that anyone Bisping has fought before with the exception of Evans and perhaps Hamill. But Bisping looks healthier at 185 than he did at 205, so we'll probably see two guys who are both better than ever before.
I think this fight is going to be decided on their feet, and it can go either way. So since Leben has the better odds, I bet my points on him...