Well I learned my lesson big time with the QuickTime 7.5 update nightmare. From now on, I do a smart clone using SuperDuper to my slave drive, on ANY update Apple puts out.

That way I can clone it back to a usable system if things go wrong, and everything that they put out , something is wrong with it. At best you get a mixed bag, some good fixes along with new bugs.

Do yourself a favor, do a SuperDuper smart clone with back up all files, before any Apple update.
Repair permissions before and after their updates.

Don't jump on an update and install it right away. Wait and see what others have to say first on macfixit.com and other blogs. Give it a week or so. What's the rush. I know, I was an instant update junkie too. You need to get that monkey off your back, it's hard, but we're pullin for ya.

If this is not sound advice, then I don't know what is.