With the release of Snow Leopard only a short time ago, many of Apples internal applications, save for a few such as iTunes and Front Row, have been rewritten in Cocoa and built as 64-bit applications. The reasons for doing so range from reluctance to retrofit major new features or fix old bugs in an application due for a Cocoa overhaul, to the obvious advantages that come with 64-bit computing; access to larger amounts of memory should it ever become necessary, and new processor features only available in 64-bit mode.
While Apple is no doubt still working on porting their flagship application to 64-bit Cocoa, the release version of iTunes 9 available from the Apple Website is apparently still 32-bit only. A quick check using some command line tools confirms there are only 2 builds present in the new binary file:
mac:MacOS steve$ lipo -detailed_info iTunes Fat header in: <strong>iTunes</strong> fat_magic 0xcafebabe nfat_arch 2 architecture <strong>ppc</strong> cputype CPU_TYPE_POWERPC cpusubtype CPU_SUBTYPE_POWERPC_ALL offset 4096 size 14546048 align 2^12 (4096) architecture <strong>i386</strong> cputype CPU_TYPE_I386 cpusubtype CPU_SUBTYPE_I386_ALL offset 14553088 size 14203136 align 2^12 (4096)
This shows that the currently released version of iTunes 9 for Mac OS X only contains PowerPC (ppc) and 32-bit Intel (i386) binaries; 64-bit support is missing. If they had rewritten iTunes to take advantage of 64-bit cocoa, you would see an x86_64 listing there as you currently see with the Quicktime X binary:
mac:MacOS steve$ lipo -detailed_info Quicktime\ Player Fat header in: <strong>Quicktime Player</strong> fat_magic 0xcafebabe nfat_arch 2 architecture <strong>x86_64</strong> cputype CPU_TYPE_X86_64 cpusubtype CPU_SUBTYPE_X86_64_ALL offset 4096 size 9512784 align 2^12 (4096) architecture <strong>i386</strong> cputype CPU_TYPE_I386 cpusubtype CPU_SUBTYPE_I386_ALL offset 9519104 size 7133744 align 2^12 (4096)
As can be seen above, the Quicktime X binary only supports 64-bit (x86_64) and 32-bit (i386) intel processors, as Snow Leopard does not support PPC at all.
It seems the Cocoa rewrite will have to wait a bit, and Apple is using this iTunes 9 release as a stopgap measure to support new features and new hardware. However they are referring to this new iTunes release as iTunes X internally, as can be seen in the package list inside the installer:
mac:Resources steve$ pwd /Volumes/iTunes 9/iTunes.mpkg/Contents/Resources mac:Resources steve$ ls iTunes* iTunesAccess.pkg: Contents <strong>iTunesX.pkg</strong>: Contents
So rest assured, a true 64-bit Cocoa “iTunes X” is coming, albeit later than the community assumed it would be released.