After a week of testing the OS X 10.5.7 update my good friend MacNut Dave over at MacNutsAndBolts.com has given us the go ahead on the install. And as always, MacNut Dave highly recommends having a backup of your data before any OS upgrade installation process.

If you are using TimeMachine be sure that it is running properly and has a valid backup of your data. I did an upgrade once and need to rollback some data and found out after-the-fact that my TimeMachine had not been running for a couple of weeks.
To perform the OS X 10.5.7 update just go to your Apple menu (top left) and go to Software Update. This will show you all of the Apple installed software on your computer that has an update available for it.