What's new in iTunes 10.5

• iTunes in the Cloud. iTunes now stores your music and TV purchases in iCloud and makes them available on your devices anywhere, any time, at no additional cost.
• Automatic Downloads. Purchase music from any device or computer and automatically download a copy to your Mac and iOS devices.
• Download Previous Purchases. Download your past music, TV, app, and book purchases again, at no additional cost. Previous purchases may be unavailable if they are no longer on the iTunes Store.
• Sync with your iPhone, iPad, or iPod touch with iOS 5.
• Wi-Fi Syncing. Automatically sync your iPhone, iPad, or iPod touch with iTunes any time they're both on the same Wi-Fi network.

System Requirements

Software:
• Mac OS X version 10.5 or later
• Safari 4.0.3 or later
• QuickTime 7.6 or later; Support for HE-AAC requires QuickTime 7.6.4 or later
• 200MB of available disk space
• HD TV episodes can only be rented in the United States
• Windows XP SP2 or later, Vista 32 bit, Windows 7 32 bit
• 64 bit editions of Windows requires iTunes 10.5 Windows 64-bit version:  http://support.apple.com/kb/DL1427.

Hardware:
• Mac computer with an Intel, PowerPC G5 or G4 processor
• 1.0GHz PowerPC G4 or faster processor is required to play Standard Definition video from the iTunes Store
• 2.0GHz Intel Core 2 Duo or faster processor is required to play HD video, an iTunes LP, or iTunes Extras from the iTunes Store
• 512MB of RAM; 1GB is required to play HD video, an iTunes LP, or iTunes Extras

Apple today also has a doc on Troubleshooting iTunes Wi-Fi Syncing.
Here's the doc with info About the security content of iTunes 10.5 has long list of fixes included for windows - security fixes for OS X are either already in or being fixed as part of separate updates for OS X soon.
(From the notes on the security issues fixed, I hope this might address some of the previously reported cases of hijacked itunes store accounts.)

Update/FYI: On Wednesday Apple released Security Update 2006-011 for OS X 10.6.x and OS X 10.7.2 that include several important security fixes related to itunes store and appleid/acct password security. iOS 5 was also released with several major security fixes. See Wednesday's news.

  

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