It's clear that Calzaghe doesn't want to fight Kessler, but I believe it is more to do with money/prestige than fear. Taylor is a more skilled fighter than Kessler in my eyes, so if that fight is made, i'll be happy.

My conclusion is that no matter what Joe does he'll be criticised:

beats Kessler......................He was not that good
beats Taylor.......................He was above his natural weight and not quite as good as people made out
beats Hopkins.....................He was old and past his best