While no one can deny that Roger Federer ended 2011 in stellar fashion—maintaining a 17-match win streak and capturing three titles—we should be hard-pressed to use this as a predictor of success at this year's Australian Open.
For one thing, Federer played his two biggest challengers—Novak Djokovic and Rafael Nadal—a total of one time during the post-US Open leg of the 2011 season. Unfortunately for Federer, at least one of Djokovic and Nadal will be a road block on the way to the Australian Open final.
In addition, Federer pulled out of the 2012 Qatar Open due to back problems—only the second time he has had to pull out of a match in his entire career. While Federer claims the injury is not too severe, that he had to withdraw from a semi-final match suggests that he may be suffering from poorer recovery times and increased bodily fatigue.
With the heat in Australia being a significant determinant of match success, Federer may not be in the shape he needs to be. Indeed, if his statements after Qatar are any indication, we can expect Federer to take a bit of a break before setting foot on a tennis court, which will be a serious hindrance to his preparation for this year's first slam.