I do think Dawson would be the clear favorite in this. Speed kills Hopkins like you said. Especially at his age. That is a bad ass avatar btw.
It's the only fight that makes sense. Dawson needs to prove himself against the best and that is what Hopkins is (at Light Heavy). Although I don't think Hopkins will take the fight as he likes to have a size advantage against his opponents. (Trinidad, De La Hoya, Wright, Pavlik, even Calzaghe)
By the time Dawson is ready to fight Hopkins (after he comes back from injury and fights Tarver), even if he drops the IBF belt too...Hopkins will be too old, imo, to even consider this fight. Dawson is not Pavlik. He is less of a draw, there's less money to be made and the risk/reward is worse for Hopkins. The fight will not happen, I don't think. Hopkins might in fact never fight again.
Hopkins is my favourite fighter but I would definately favour Dawson in this match up. Hopkins was able to make fighters like Tarver and Pavlik look bad because he was able to use his movement to ensure they were never in a position to let there hands go. Dawson not only has fast hands but fast feet as well, Hopkins will not be able to keep the quicker Dawson at the range he would prefer and much like against Calzaghe will get out worked. I would be very suprised if Hopkins made this fight and even more suprised if he won. Though it would still be a fight I'd like to see.
i honestly think b hop would out fox dawson and win by ud,but if dawson did win it may tempt calzaghe for one last battle,and then would bring the money.(in Cardiff of course).