It's a well known fact that geeks like to put Linux on everything, including toasters, and they also like anything built around Firefox. This explains why they've gabbed about Songbird since it was version 0.0001. Songbird, available for all major desktop operating systems, builds upon Firefox to make something that flirts with iTunes functionality - it can play your music collection, but rather than shilling an online store, it scours the web for new content, linking you to music blogs and cataloguing the available content for streaming or downloading and saving you from having to read the dull text contained therein.
Songbird 0.2 was just recently released. I used the 0.1 version and it didn't cause my computer to explode, so you've a good chance of avoiding injury by using this beta software. They've also provided a movie demo of the features. Be sure to watch until the end when the presenter goes mildly insane with power.