I had UNO already installed, and then I installed iTunes 7. It works fine that way.
I bet iTunes 7 has a lot of interface elements that will be in Leopard. For instance, the scroll bar. iTunes has always used the standard scroll bar, but now it's changed. If Leopard is going to look like iTunes 7, I'll love it.
I pray to god that 10.5 won't get those scrollbars. If they want smooth looking bars, the least they can do is use the ones in the "Milk" themes. These ones are horrible... I can't wait for a new version of UNO to come. Just too bad you have to install an application fix Apple's mess, as the Apple experience should be about the "out-of-the-box".