Apple today released Mac OS X 10.6.5 which is available via Software Update and contains the following improvements:

• Improves reliability with Microsoft Exchange servers.
• Addresses performance of some image-processing operations in iPhoto and Aperture.
• Addresses stability and performance of graphics applications and games.
• Resolves a delay between print jobs.
• Addresses a printing issue for some HP printers connected to an AirPort Extreme.
• Resolves an issue when dragging contacts from Address Book to iCal.
• Addresses an issue in which dragging an item from a stack causes the Dock to not automatically hide.
• Resolves an issue in which Wikipedia information may not display correctly in Dictionary.
• Improves performance of MainStage on certain Macs.
• Resolves spacing issues with OpenType fonts.
• Improves reliability with some Bluetooth braille displays.
• Resolves a VoiceOver issue when browsing some websites with Safari 5.
• Improves Bluetooth pairing with Magic Trackpad.
• Resolves performance issues with third-party displays that use InstaPort technology.
• Add SSL support for transferring files with iDisk.
• Resolves an issue when opening 4-up Photo Booth pictures in Preview.
• Addresses keyboard responsiveness issues in the Dock when Spaces is turned on.
• Resolves an issue syncing Address Book with Google.
• Fixes an issue when replying to a Mail message sent by a person whose name contains certain characters such as é or ü.
• Improves performance for users bound to an Active Directory domain.
• Improves reliability of Ethernet connections.
• Systems with a Mac Pro RAID Card (Early 2009) installed can now be put to sleep.
• Improves reliability of fibre channel connections, resolving a potential Xsan volume availability issue.
• Adds RAW image compatibility for additional digital cameras.

This update also includes the improvements found in the Mac OS X v10.6.1, 10.6.2, 10.6.3, and 10.6.4 updates.

More info here.