"iTunes 9.1 comes with several new features and improvements, including:

Sync with iPad to enjoy your favorite music, movies, TV shows, books and more on the go

Organize and sync books you've downloaded from iBooks on iPad or added to your iTunes library

Rename, rearrange, or remove Genius Mixes
System requirements: OS X 10.4.11 or later "

There's also a doc About the security content of iTunes 9.1. (iTunes 9.1 also available for windows.)

"QuickTime 7.6.6 for Leopard (OS X 10.5-10.5.8)
QuickTime 7.6.6 is recommended for all QuickTime 7 users and includes changes that increase reliability, improve compatibility and address security, including:

• General reliability improvements for iMovie

For information on the security content of this update, please visit this website: About QuickTime 7.6.6
System Requirements: OS X 10.5 or higher"

Here's the actual doc with details About the security content of QuickTime 7.6.6.
I had installed QT 7 (optional) when I upgraded to Snow Leopard and the (Combo in my case) OS X 10.6.3 update included QT 7.6.6. (QT 7 player is in utilities folder. QT 10 is in apps folder.)

" iPhoto 8.1.2
This update addresses minor issues in the area of import and syncing to iPhone, iPod or Apple TV.
System Requirements: OS X 10.5.6 or later"

For details on changes see About the iPhoto 8.1.2 Update.

• Mac OS X 10.6.3 Packs Some Regressions (some odd reduced performance in their OpenGL test w/mac mini (9400M))
• iPhone HD Could Be Apple's Next-Generation Smartphone
• Apple iPod Chief's Official Departure Marks End Of An Era
• Managing iPad Security Weaknesses
• iPad Camera Connector Clones Five-Year-Old iPod Version
• WSJ's Lame Entry in the iPhone Rumors Game
  
  Apps/Misc. Software Updates: (see above for iTunes, QT and iPhoto updates)
• iPhone Configuration Utility 2.2 for Mac OS X
• Free App of the Day for Mar. 30th is Scribattle
• Picasa 3.6.5.203
• X11 2.5.0
• Thunderbird 3.0.4
• Keyboard Maestro 4.2
• iPhone Configuration Utility 2.2 for Windows
• MobileMe Control Panel (v1.5.1) for Windows

• About the iPhoto 8.1.2 Update
• About QuickTime 7.6.6
• About the security content of QuickTime 7.6.6
• About the security content of iTunes 9.1
• How to identify Mac mini models
• MobileMe Gallery: Can't see Syncs With field in Album Settings at me.com/gallery
• VoiceOver Kit for iPod
• Final Cut Studio (2009), Final Cut Pro 7.0.1, & 7.0.2 with Mac OS X v10.6: Final Cut may stop responding when capturing DVCPRO HD via FireWire
• Final Cut Studio (2009), Color 1.5: Upgrading a Color 1.0.x project to 1.5.x changes any existing Trackers
• MobileMe: Alert on Windows computer when using a proxy server
• MobileMe (Windows): "CoreFoundation.dll was not found" or " Apple Application Support is missing" alert
• MobileMe: Troubleshooting Windows syncing
• iTunes for Windows: Troubleshooting security software issues

• Amazon's 'Frustration-Free' Packaging Leaves a Trail of Dead Disks
• Five products designed to fail early (or go obsolete...)
• Microsoft defends Windows 7 security after Pwn2Own hacks
• Battlefield: Bad Company 2 VIP map pack available
• Modern Warfare 2 DLC is broken
• Zune 4.5 firmware coming 'soon'
• Zune HD 64 shows up