Mac OS X 10.5.2 (Build 9C31) was released on Monday, February 11th.

1. Leopard Graphics Update download (49Mb) becomes available in Software Update after you install 10.5.2. Reboot also required. If you're having trouble installing the update through Software Update, try downloading and installing the update from Apple's website.
   
   
   
2. Apple has posted the Combo Updater download (343MB). If your having trouble installing the update through Software Update, try downloading and installing the update from Apple's website.
   
   
   
3. Turn off Menu Bar transparency in the Desktop & Screensaver Control Panel
   
   
   
4. Time Machine may say "Preparing..." for an extended period of time when it tries to backup after the update. This has been observed as normal, and it will succeed.
   
   
   
5. Mac OS X: Software update sizes can vary. Sizes for the update may range from 180-340MB. See Apple technote explanation
   
   
   
6. If you go to About Finder it will say Finder Version "10.5.3". This is normal: Finder is just an application and its version number may be different from the OS version.

Source: Mac OS X 10.5.2 Fixes, Bugs and Problems

See Also:

Mac OS X 10.5.2 Fixes and features

Mac OS X 10.5.2 Possible issues