Apple has finally released 10.6.5 update for Snow Leopard yesterday, 10th of November. Fixes reliabilty with Microsoft Exchange servers and image processing in iPhoto and Aperture among other things.
UPDATE: Updated 10.6.5 smoothly. Retail Pack 1.0 (even EFI, HF7c) didn't pose any problem. 311 restarted and rebooted back to desktop without a kernel panic. Booting with install to root method (via Lizard) should work as flawlessly. I used the combo updater (1GB in size).
Per usual procedure, back up before you try out the update. However, I believe Retail Pack 1.0 is resilient to this new system update anyway.
The dmg file, for the delta version (for incremental update; 10.6.4 -> 10.6.5) is around 650 MB but the combo update (10.6.3 and earlier -> 10.6.5) is a hefty download of around 980 MB (1 GB almost).