It's a well-deserved award. Pavlik earned it by winning three fights, as the underdog in two of them and winning the middleweight title against Jermaine Taylor. Many people considered Taylor in the top 10 p4p prior to the fight.
Cotto had a great year and won two fights I did not expect him to win and were it not for Pavlik my vote for fighter of the year would go to him. The Mosley fight was a great showing by Cotto though, so I can't really argue with those who pick him.
Floyd had two impressive victories, but many people expected him to beat ODH and most picked him to beat Hatton. Beating Oscar was impressive, but IMO not as impressive as Pavlik beating Miranda, which I'm still pissed off about, and Taylor and knocking both of them out. Maybe I'm just too used to PBF winning to be as impressed as I should be.