*rimshot* Good one!Cook made the short list? He looks taller on stage.
On Topic: I can't think of many people who should be on the list. A lot happened this year, and I think I'm kind of leaning towards Barack Obama because of the election (which seems like a lazy, but solid choice) or Malala because of the broader issues she represents: violence against women, violence against children, the struggles of people around the world to get an education, the ongoing fight against senseless extremists.
But... Tim Cook? I would loose any respect I have for Time if they chose him as the most important person of 2012. They may as well select George Lucas for selling Star Wars to Disney at that rate.