Apple has released an iTunes update and describes pretty explicitly (for Apple) what the fixes are, like the issue with the zoom button, unexpected quits, and unresponsiveness, the latter two of which I experienced a couple few times.
Tell you one thing. It installed a lot faster on Leopard than it did on Snow Leopard.
Now, did they fix the discrepancy with displayed track sizes versus displayed Finder file sizes under Snow Leopard (my pet radar report)? No: