fudged my MB Air for a while
After the update downloaded and installed fine, rebooted and screen was ghostly white and no keyboard input to login window, only mouse movement possible.
Another reboot and the color got even more whited out.
After waiting cpl more minutes, screen color returned to normal and previously entered keystrokes flooded the login box.
All is fine now, and hopefully the MB Air issues documented to have been fixed in this update will help those messed up issues.
I still LOVE my 13" latest model MacBook Air and OS X, etc, but feel Apple really has been releasing things too quickly without paying as much attention to QC testing as before.
Still, I have been using an Android tablet/phone (Dell streak) recently, and Apple is still the most stable platform out there on PCs and mobile devices...