After nearly half a year of continuous MacBook Pro crashing for unknown reasons I have finally figured out and repaired the problem.
The problem exists with a lot of users (judging by the number of posts in the Apple Support forums) that have upgraded from previous versions of OSX to 10.8.x.
The crashing for most is caused by multiple versions of Safari (mostly WebKit).
To fix the problem:
- Navigate to System > Library > StagedFrameworks > Safari in Finder.
- Delete any WebKit frameworks.
- Run system update and install the Safari update. DO NOT RUN SAFARI.
- Reboot your Mac.
This corrected my problems so far. Will keep you posted.