"Leopard Graphics Update is recommended for all users and improves the stability and compatibility of your Mac. This update requires Mac OS X 10.5.2."

If anyone (especially 2008 Mac Pro owners w/ATI 2600 XT cards) finds this update (and/or 10.5.2) helps (or not) let me know. Thanks.
Update - I've posted a page of initial Feedback on 10.5.2/Graphics Update that has 2008 Mac Pro owner reports in a separate section. (Unfortunately initial feedback from those with graphics/freeze problems, restart on wake, etc. said these updates did not help, although those w/o problems noted some benefits. (Page includes general reports, notes on an issue with Linotype FontExplorer X 1.2.2, benefits seen by a WoW user and a Lightwave 3D v9.3 user.)

• Mac OS X 10.5.2 Combo Update
• Mac OS X Server 10.5.2 Combo Update
• WebObjects Update 5.4.1 for Mac OS X 10.5
  
  And related docs
  
  
• About the Mac OS X 10.5.2 Update
• About the security content of Mac OS X 10.5.2 and Security Update 2008-001
• About the Mac OS X 10.5.2 Server update
• Mac OS X 10.5: Digital camera RAW formats supported
• Mac OS X 10.5: Dashboard widgets issues with Parental Controls and Fast User Switching enabled (says fix is 10.5.2)
• Mac OS X 10.5.2: Server Monitor and ipmitool cannot connect to server

I installed the (300+MB) 10.5.2 Combo updater on an AL iMac here, saw a 'double restart' initially (seen that before at times with my G5 tower) and then I applied the Leopard Graphics update. So far everything seems fine. With 10.5.2 the option to shown Time Machine in the menu bar was enabled by default also - I leave TM off and just use the "backup now" option once a day or so. (And just as an FYI for Matt - a verify permissions afterwards was totally clean - no messages - for the first time...)

• The MacBook Air finds its Nietzsche (infoworld)
• The Gadget Master: The MacBook Air (daily colonial)
• Tyler Tech: MacBook Air doesn't live up to price (towerlight)
• Battlefront Mod Installer 0.3.1
• Warcraft III: Reign of Chaos 1.21b
• Warcraft III: The Frozen Throne 1.21b
• Mac Pilot 2.5.3
• Hidden Relics 1.0.2
• Hidden Secrets: The Nightmare 1.0.2
• GrabBack 1.3.2
• Netflix Opts for Blu-Ray High-Def DVDs