Apple released iTunes 10.4 Wednesday, and the number one change in the new release is that the software is now 64-bit in Lion and 64-bit Windows Vista and Windows 7. Other enhancements include support for Lion’s full-screen mode.
Apple’s patch notes:
What’s new in iTunes 10.4
iTunes 10.4 is now designed for OS X Lion. You can now use iTunes with OS X Lion’s new Full-Screen App capability, which allows you to use iTunes and other without distractions. Navigate between your full-screen apps with a simple gesture.
iTunes is now a 64-bit Cocoa application on OS X Lion and includes a number of important stability and performance improvements. Some iTunes plug-ins may no longer be compatible with this version of iTunes. Please contact the plug-in developer for an updated plug-in compatible with iTunes 10.4.
Windows
iTunes 10.4 provides a number of important stability and performance improvements.
The patch notes for the Windows version stipulate that the 64-bit version only works with 64-bit versions of Windows Vista and Windows 7, and that 64-bit Windows XP is not supported. Windows users can update through the Apple Updater utility on their PC or through Apple’s Download site (32-bit users should use the main iTunes 10.4 KnowledgeBase article while 64-bit users should use the dedicated KnowledgeBase article for the 64-bit version).
Mac users can update through Software Update (64.1MB download), or through the standalone installer from the update’s KnowledgeBase article (90.23MB).