Its quite early to make a pick, but if Campbell beats Guzman convincingly then he'll be the frontrunner. Mijares could also make a claim if he beats Montiel clearly.
Pac for me at this point. Campbell, Pavlik & Vasquez got SD's over their opponents. Difference is I rate JMM above their opponents whom Pac also got an SD over, plus he has a dominating performance over David Diaz. Mijares is lacking A quality opponent, Munoz is a B at best.
Pac so far IF the valero fight goes through and pac beats him, it will solidify pacs claim as the fighter of the year.