iTunes 10.4 is available and ready for Lion
iTunes 10.4 is now available via Software Update, bringing with it full-screen app capability. Plus, iTunes on the Mac is now a 64-bit Cocoa app in Lion. If you're using some older iTunes plug-ins you may have issues with those (according to Apple). Makes sense, as Lion has shed many vestiges of OS X versions past.
We'll update this post with direct links when available.