Great idea, glad someone snagged the API to work with for OSX.
BUT, did five batches of songs, of about varying sizes (got larger the more confident I was). Three were flawless, the fourth had every song renamed one off (so the playing song is actually named for the one beneath it) and the fifth was pretty randomly renaming songs. It renamed songs not even in the list.
So, while I was initially pretty hacked that I had to rename these songs, it's beta, it's free, it's a good idea being worked on. Keep it to small batches, maybe one Artist at a time, and don't blame the developer for any of the results you get, it's not his database. And for pete's sake, can we get a new icon for 1.0? C'mon. :)