Does 10.6.3 add the ability to install or download iOS 6? I'm pretty sure you still need to download the IPSW from Apple's dev site first.

Quote:

Originally Posted by AppleInsider 

Apple on Monday released iTunes 10.6.3 to aid developers in downloading the new iOS 6 beta.
Amidst the deluge of product launches and announcements like the next generation MacBook Pro, Apple released the latest update to its iTunes media manager, though the new version is mostly tailored for developers with access to iOS 6.
While iTunes 10.6.3 only adds the ability to download the new iOS 6 beta, consumers can download the update directly from Apple's website. As of this writing, the software isn't being pushed out via Software Update, but that may soon change by the end of the day.
Besides the addition of iOS 6, no significant changes have been made to iTunes though some bug fixes have been addressed.
From the release notes:

iTunes 10.6.3 includes support for OS X Mountain Lion and addresses a number of important issues:
? Addresses a problem where iTunes may become unresponsive when syncing an iPad (1st generation) that contains an iBooks textbook
? Fixes a problem where photos synced to a device may appear in an unexpected order
? Resolves an issue where iTunes may unexpectedly delete playlists created on a device
? Fixes issues where iTunes may unexpectedly delete apps on a device
? Improves overall performance and reliability

Apple's next-generation mobile operating system is slated to be ready for public consumption later this fall and will include over 200 new features including updated Siri functionality, a new proprietary maps app and system-wide Facebook integration, among others.

Interestingly, with all thee fixes it still leaves in the giant bug wherein it will constantly ask you for your password to enable automatic downloads even when you have automatic downloads turned off. It's like a six month old bug and they still didn't fix it.  Quality! 

Still doesn't know how to load album art properly...

Itunes is a MESS. Apple seriously needs to re-think this decade old interface. Too many "stores", too confusing for users who have acquired multiple user accounts, iCloud interface is sloppy, it's like trying to run a Windows 95 application under Windows 7 ... I mean iTunes is like going to the start menu to shut down ... It's a music interface that handles Apps, Movies, Books, and synchronization for multiple devices that do more than play music ... It's really hard to believe Apple has gone this long without a complete overhaul ... I really hoped Mountain Lion would address all the inadequacies of the current abomination.