The latest update to Mac OS X “Leopard”, version 10.5.4, is now available via Software Update in the Apple menu or by direct download. Main areas of change include: Airport, iCal, Safari, Spaces and Exposé. Details are available here:
It is available via Software Update in the Apple menu at the left end of the menu bar, or you can download the Combo Updater that also includes all previous Leopard updates and which have, in the past, proven to be somewhat more reliable in terms of avoiding potential problems. It’s probably also not a bad idea to launch Disk Utility (in the Utilities folder in Applications) and run both Verify Disk and Repair Permissions on your boot disk before applying the update.
I’ve just successfully applied the combo updater on two machines: a G5 tower and a MacBook Pro. Report your experiences in the comments section for this post.
NOTE: If you use an Apple Airport Extreme, Express or Time Capsule base station be sure to launch Airport Utility in the Utilities folder after performing this update so it can upgrade the base station firmware.