I'm having a very similar (the same?) issue. I can be browsing the web, using evernote, spotify, or practically any application, and I'll experience a crash. By crash, I mean: All applications are no longer responsive. I can move the mouse, but I can't click on anything. I have to shut down by holding down the power button. When the computer restarts, it prompts me with something like "the computer detected a graphics problem, would you like to report it to apple?". I always report the issue.
I have a Macbook pro, retina, 15", late 2013, 2.3 ghz core i7, 16gb ram, geforce gt 750M 2048 MB. I'm running 10.10.1.
I'm going to disable "automatic graphics switching" under Energy Saver and see if that fixes the issue.
I have an open case, the ID is 735100717.
If Engineering could bump up the priority on the bug reports associated with this thread, that'd be great. Thanks!!