Windows update applied KB2393802 around 03:00 and my system no longer boots. I recovered using System Restore in Safe Mode. We've had one other report of this inside IBM, but it's early in the day yet.
It may not be KB2393802; here is my list of fixes applied:
KB2393802
KB2478960
KB2476687
KB2482017
KB890830
KB2483185
KB2479628
KB2485376
KB2492441
KB2478971
Forgive me if there is a better place that this; I rarely come here.
Steve Swift