My 15" rMBP freezes several times a day with the same issue. Seems to be a graphics issue. I've tried reinstalling from scratch but nothing has worked. I contacted Apple after a couple months, but they wouldn't replace it. Then I wasted more time with an "high level" Apple customer support person. They had a tech look at my logs, and he pretty much agreed there was a graphics issue.
The customer service rep pretty much wasted my time and said they'd only repair the machine, same as the Apple store genius told me. This was probably 4 months ago, and it's frustrating, but I don't want to be without my computer for a few days, so I haven't taken it in yet. On top of that, my display has the "image retention" problem like a plasma display used to have.
It's pretty frustrating to spend all this money and get a bad machine and no help from Apple. I've probably had 20 Apple computers in my life, this has been the worst experience by far.