I’ve recently had a few issues where the Mac has crashed with a “GPU Panic”.
Turns out it might be something to do with Google’s Chrome browser which uses some GPU acceleration for HTML5 updates.
For the moment I’m going to uninstall Chrome and see what happens.
Also experienced an annoying logout problem which also happens to be related to the GPU and GPU switching. If you’re using multiple GPUs then you can use gfxCardStatus to fix the Mac to 1 GPU.