4) Josh Hamilton. Hamilton already had an interesting career path through one year ago, but it's even more so now. See, Hamilton's injury problems last year spread his rookie season out in a way that arguably prevented the league from adjusting to him. Hamilton missed two weeks around Memorial Day, five weeks in July and August, and the last two weeks of the season. Hamilton played more than six games against just three teams, and against two of those, the Astros and Pirates, he posted terrible overall lines.
Getting traded to the Rangers over the winter extended this nominal honeymoon period new league, new pitchers, new faces. Hamilton is off to a .330/.379/.591 start, comparable to last season's, but I think it's important to note that he hasn't had to go through the adjustment period many young players do.
Hamilton is a fantastic story and obviously a tremendous baseball talent. In his career, though, he hit .295/.342/.476 in the minors, and he's at .303/.371/.564 in the majors, all of that coming after playing not a lick from 2003 through 2005, and getting just a few weeks of play in 2006. There's enough wackiness in that kind of information, and in his path through two leagues over the last 13 months, to warrant some healthy skepticism about his ability to sustain his performance.
I guess he's probably right, but from what I've seen of watching Hamilton bat, he's making adjustments during AB's let alone from team to team. I think an OPS around .900 is not too much to hope for from Hamilton.