This can be almost anything you want it to be. It could be a new 2011 recording (any format) or an old pressing (any format) you obtained. It could be a concert highlight (any genre). It could be a situation whereby you found yourself developing more of an interest in digital>analog or analog>digital and that presented you with an eye opening experience.
One of the highlights for me was that I learned to have more respect for the digital domain. And while my preference will always be vinyl, I have discovered that when done right, digital is most rewarding. As such, I can see that part of my library growing considerably.
Please share with me some of your 2011 highlights.