Yes, Assange made a distinct impact on the news and world events this year, but his face has been all over for this reason and that for weeks, and I think people are kind of sick of it. On top of that, he's hardly what one would call media friendly.
Facebook may seem like old news to us but, IIRC, it was this year that they crossed the 500M user mark. That's a pretty big deal. It sucks up 700 billion man-minutes a month, and that's only getting more out of control.
In hopes of avoiding a rant, let's just say this: if you had to write a major, year-defining (culturally, and for your publication) profile of someone, would you do it about the media figure with a hit movie "about" his life or the guy who has a tendency to walk out on interviews when he doesn't like a question?