Actually, iTunes has been able to use a network drive for quite some time.
You just enter //servername/sharename into the library location.
iTunes happliy resets the library location to the default location when ever it feels like it. This behaviour becomes extremely annoying by about the third time you have to re-enter your music library location
Yeah, I wasn’t sure how long they’ve had that, so I was hesitant about being specific 🙂 . So far, I haven’t been burned by iTunes reseting the library location.