The update is available in the Apple folder. It is closed to 30 meg so get it from an FTP site if you are able to. I have installed it on a few machines. No problems so far. Run repair before installing and read the gotcha notes that Apple always includes. Also make sure that your hard disk drivers are updated. There really isn't much added for most of us other than the advertised improved reliability. If all the install machines at the office and my personal machine hold up through Saturday I may install it on the Headgap Server.
Here is a couple of helpful URLS, the last two are the download sites, the very last is CNET's