What's included?
General
* Includes recent Apple security updates.
* Addresses stability issues with video playback, processor core idling, and remote disc sharing for MacBook Air.
* Addresses an issue in which some Macs could unexpectedly power on at the same time each day.
* Resolves a stability issue in TextEdit that could be found when accessing the color palette.
* Improves Spotlight indexing performance.
* Fixes an issue in which contacts might not sync properly with PalmOS-based devices.
* Improves iPhone sync reliability with iCal and Address Book.
* Includes improvements to Active Directory (see this article for more information).
* Improves Speech Dictionary.
* Fixes Kerberos authentication issues for Mac OS X 10.5 clients that connect to certain Samba servers, such as Mac OS X Server version 10.4.
* Includes extensive graphics enhancements.
Address Book
* Addresses stability issues that may occur when creating a Smart Group.
* Resolves a printing issue with address cards containing information that spans more than one page.
Disk Utility and Directory Utility
* Improves reliability when rebuilding a software mirror RAID volume in Disk Utility.
* Improves reliability of server status displayed in Directory Utility.
iCal
* Updates iCal to more accurately handle repeating events.
* Improves performance when choosing meeting attendees.
* Resolves an issue in which the "Refresh All" option may be dimmed ("grayed out") in the contextual menu for certain calendars.
* Fixes issues with read-only calendars.
* Addresses an issue that prevents an invitee from moving an event to a different calendar.
* Resolves an issue with syncing published calendars.
Mail
* Addresses performance issues related to displaying IMAP messages.
* Resolves an issue with SMTP settings for AIM, Compuserve, Hanmail, Yahoo!, and Time Warner Road Runner email accounts.
* Addresses stability issues that may occur when dragging a file to the Mail icon in the Dock.
* Addresses an issue with the "Organized by Thread" view in which the date does not appear when the thread is collapsed.
* Resolves an issue in which RSS feeds could temporarily disappear from the sidebar.
* Improves Mail robustness when sending messages.
* Improves reliability when saving drafts that have attachments.
MobileMe
* Improves overall sync reliability.
* Improves Back to My Mac reliability.
Time Machine
* Improves Time Machine reliability with Time Capsule.
* Addresses performance issues that may affect initial and in-progress backups.
* Fixes an issue in which an incorrect alert message could appear stating that a backup volume does not have enough free space.
* Time Machine can now back up iPhone backups that are on your Mac, as well as other items in (~/Library/Application Support).