For 2013, I will be taking a very close look at Hamilton and Mercedes. I don't expect them to be bagging the championship, but I will be looking to see if Hamilton has what it takes to galvanize the team.
Thinking about what makes a great driver,for Formula 1, I've come to add team management into the mix in addition to pure on-track skill. Since everything in Formula 1 is down to inching that extra tenth, team interaction and building is just as important as developing parts and the racing line. You think of the greats: Clark, Senna, Schumacher, Alonso, you see that these drivers were able to rally a team around them. This matters for development, pit stops, and morale. Vettel, in this case, has taken advantage of the opportunity to do the same: get himself not just a great car, but one that is tuned to HIM and a team that supports him 110%.
With that in mind, I am looking to Hamilton to prove that he, with the experience, can wrestle with the Mercedes team to maturely....mature the group into top contention. I don't know the particulars of his personal background (his dad, his lady, etc.) but I predict that Hamilton will see himself with the chance to mold the team in his image, and he will show his growth as an overall team leader. At least 1 win, with consistent points finishes on merit (barring incidents and reliability) for the team as a whole (including Nico).