On Answer.com Amarok page, it states that:
Playing a song with the tag title as “Amarok” and the tag artist as “Mike Oldfield” produces the following OSD popup:
“One of Mike Oldfield’s best pieces of work, Amarok, inspired the name behind the audio-player you are currently using. Thanks for choosing Amarok!
Mark Kretschmann Max Howell Chris Muehlhaeuser The many other people who have helped make Amarok what it is”
So I decided to test it out, here is a screen shot:
Oddly enough, Answer.com states that their source is Wikipedia, but this easter egg does not appear in the Amarok article of wiki.