Yes the screen shows you all your library info like an iPod's screen. You can sort you library by the usual iPod/iTunes categories like album, artist, playlist, genre etc. The remote acts as a conduit for controlling what gets sent via bluetooth to the receiver, or to your soundcard in "local" mode. You can have more than one receiver as well and choose between "rooms" to send your music.
Perhaps a way to do this would be to export library info from MC to iTunes and then just use the wireless DJ as intended. Can MC save playlists/library info in a way iTunes understands seamlessly? If not, I guess I could always just use another 80GB of space and duplicate my files.... or refuse to let iTunes organise my music (which MC will do), and just be able to see it.