TUAW has an article about how to get Notification Center to show what music is playing. This works with iTunes and other services like Spotify. They mention “Now Playing” from Mediafire. It is an AppleScript way to get the Notification Center in Mountain Lion to list the song title.
They write about iTunification from Onible. It is similar to Now Playing but displays the current track and artist. It also has a Growl option.
Both of these are scaled down from GrowlTunes which adds playback controls to the menu bar and uses Growl to display the information.
Of course, there are links to these items on their web site. See it here: