I think both fighters should stay at 160.

Pavlik just became middleweight champ, it's arguably the second most prostigious title in boxing (after heavyweight champ), he should stay there and defend it.

Taylor keeps saying he wants/needs to move up to 168, but I don't see him having much success there. Generally, the fighters who can move up effectively to higher weight classes are slick boxers who can beat bigger guys with movement and defense.

Taylor is not a slick boxer. In fact, his biggest attribute has always been his size. He's beaten 160 pounders because he's bigger, stronger, taller than most other middleweights. If he moves up, he'll no longer be fighting tons of guys who are smaller than he is.