Apple has posted the Mac OS X 10.5.7 Update package to its Software Update servers, weighing in at a hefty 449MB just for the incremental update from 10.5.6. Combo packages are also available both for the standard (729MB) and server (951MB) variants from Apple’s Downloads Page.

Readers are encouraged to report on any problems or changes.

From release notes for the standard Delta Update package:

What’s new in this update?

Address Book

* Improves reliability of Address Book syncing with iPhone and other devices and applications.

AirPort

* Improves the reliability of AirPort connections, including improvements when roaming in large wireless networks with an Intel-based Mac.

Client management

* Improves reliability of synchronizing files on a portable home directory.
* Fixes an issue in Mac OS X 10.5.4 and 10.5.5 in which managed users may not see printers that use the Generic PPD.
* Client computers that use UUID-based ByHost preferences now respect managed Screen Saver settings.

iChat

* Addresses an issue that could cause an encryption alert to appear in the chat window.
* Setting your iChat status to “invisible” via AppleScript no longer logs you out of iChat.
* Resolves an issue in which pasting text from a Microsoft Office document could insert an image rather than text.

Graphics

* Includes general improvements to gaming performance.
* Includes graphics improvements for iChat, Cover Flow, Aperture, and iTunes.
* Includes fixes for possible graphics distortion issues with certain ATI graphics cards.

Mail

* Includes overall performance and reliability fixes.
* Improves Connection Doctor accuracy.
* Fixes an issue that could cause messages identified as junk to remain in the inbox.
* Fixes an issue that could cause Mail to append a character to the file extension of an attachment.
* Addresses an issue that could prevent Mail from quitting.
* Improves reliability when printing PDF attachments.

MobileMe

* Contacts, calendars, and bookmarks on a Mac automatically sync within a minute of the change being made on the computer, another device, or the web at me.com.

Networking

* Improves Apple File Service performance, especially when using a home directory hosted on an AFP server. Important: If you are using Mac OS X 10.5.6 (client) to connect to a Mac OS X Server 10.4-based server, it is strongly recommended that you update the server to Mac OS X Server version 10.4.11.
* Improves the performance and reliability of TCP connections.
* Improves reliability and performance for AT&T 3G cards.
* Updates the ssh Terminal command for compatibility with more ssh servers.

Printing

* Improves printing for the Adobe CS3 application suite.
* Improves printing for USB-based Brother and Canon printers.

Parental Controls

* Addresses an issue in which a parentally-controlled account could be unable to access the iTunes Store.
* Includes general fixes for time limits.
* Resolves an issue that prevented adding allowed websites from Safari via drag and drop.

Time Machine

* Fixes issues that could cause Time Machine to state the backup volume could not be found.
* Improves Time Machine reliability with Time Capsule.

Safari

* Improves compatibility with web proxy servers.

General

* Includes Mac OS X security improvements. See this website for more information.
* Addresses inaccuracies with Calculator when the Mac OS X language is set to German or Swiss German.
* Improves the performance and reliability of Chess.
* Improves DVD Player performance and reliability.
* Performance improvements for iCal are included.
* Fixes an issue when running the New iCal Events Automator action as an applet.
* Adds a Trackpad System Preference pane for portable Macs.
* Improves compatibility with smart cards such as the U.S. Department of Defense Common Access Card.
* Updates time zone data and Daylight Saving Time rules for several countries.

Several readers have reported problems — many of them quite serious, including the apparent complete wiping of the System directory after applying updates (both Delta and Combo packages) on recent-model Macs with nVIDIA chipsets (DDR3 800/1066 memory). Both desktops and laptops appear to be affected, including current-model Macbooks, Macbook Pros, iMacs, and Mac Minis.

This is particularly surprising and ironic because one of the primary objectives of Mac OS X 10.5.7 “Juno” was to improve both the stability and performance of those exact Macs through better drivers & other hardware-related support code for their nVIDIA chipsets/GPUs!

Among many other notable changes, several developers have reported that as expected, the new Bluetooth support in Juno contains numerous drivers and other code paving the way for Bluetooth 3.0 hardware in Macs expected to ship before 10.5.8 does (roughly September 15th, according to current roadmaps for Project Athena). This, in turn, suggests that we might see the powerful, range- and bandwidth-extended wireless connectivity technology in more than just new iDevices at next month’s WWDC….

Also released alongside Mac OS X 10.5.7 are Safari 4.0 Beta “Update 2,” WebKit r43605 (latest nightly build, improves compatibility with 10.5.7), Safari 3.2.3, and Security Update 2009-002 for Mac OS X 10.4.x “Tiger.”

We will be paying close attention to reader reports submitted to us via email, Twitter, or web comments on these new packages and will do our best to keep you updated on all the latest. Stay tuned for several upcoming reports on development of Mac OS X 10.5.8 “Athena,” the latest Mac OS X 10.6 “Snow Leopard” builds, new iPhone OS 3.0 beta, and what we can expect from next month’s World Wide Developer Conference (WWDC, June 8-12)….the next few weeks are going to be a particularly exciting time for rumor-mongers & the Mac community in general, so check back often and don’t forget to Follow Us on Twitter if you haven’t already!