I think Calzaghe beats Hopkins more easily than he beat Kessler. Yes, what Hopkins has done at the age of 43 is amazing, but that is irrelevant in regards to his competitiveness versus Calzaghe. After losing to Taylor twice, what has Hopkins done really? Beating Tarver, who has not looked impressive since beating RJJ, who had to lose a bunch of weight after filming the Rocky movie. Beating an aging Winky Wright, a blown-up Middleweight at best. Calzaghe's work-rate is impressive though people will point to B-Hop negating Winky's work-rate - but I'm not convinced that the weight didn't play a bigger role in that than B-Hop did. Both fighters are masters at adapting to their opponents, but I think Calzaghe will have power and speed on his side, and that makes for a big hill to climb for Hopkins.
By no means will it be an easy victory for Calzaghe, and though its surely not impossible I don't see how this incarnation of B-Hop will win.