Apple today released Mac OS X 10.5.8, an update to their Mac OS X Leopard operating system, this update is a rather small update, only 165MB but I’d suggest waiting before updating because it’s possible that 10.5.8 has removed the ability to jailbreak devices again like what happened on 10.5.6 and then you’ll have to wait for 10.5.9 to come if ever! so please wait for a while until we are sure jailbreaking is still possible.

what this update includes:
The Mac OS X v10.5.8 Update is recommended for Mac OS X v10.5 Leopard users and includes general operating system fixes that enhance the stability, compatibility and security of your Mac.
Additional Information
- Upgrades Safari to version 4.0.2.
- Improves the accuracy of full history search in Safari 4.
- Resolves an issue in which certain resolutions might not appear in the Display pane in System Preferences.
- Dragging an Aperture image into Automator now invokes an Aperture action instead of incorrectly invoking an iPhoto action.
- Resolves an issue that could prevent importing of large photo and movie files from digital cameras.
- Improves overall Bluetooth reliability with external devices, USB webcams and printers.
- Addresses an issue that could cause extended startup times.
- Improves iCal reliability with MobileMe Sync and CalDav.
- Addresses data reliability issues with iDisk and MobileMe.
- Improves overall reliability with AFP.
- Improves overall reliability with Managed Client.
- Improves compatibility and reliability for joining AirPort networks.
- Improves Sync Service reliability.
- Includes additional RAW image support for several third-party cameras.
- Improves compatibility with some external USB hard drives.
- Includes latest security fixes.
read Apples own post :
http://support.apple.com/kb/HT3606