As said, like many other applications these days, it's actually not a complete player with a multimedia playing engine of its own but only a front-end. A Qt written GUI that relies on few multimedia frameworks such as Gstreamer, Phonon and other players such as VLC, Xine as well.
Anyhow, I think simultaneous to the upcoming KDE 4.7 release, Amarok and a lot other applications are receiving updates accordingly. Like two days ago Amarok was updated to its latest version 2.4.2 Beta 1 which brings bug fixes and some new features such as ...
*. New backgrounds.
*. Re-polished GUI.
*. Few updates to dynamic play-list (prevent duplicate track loads, Quiz-bias features that has the ability to play a multimedia file that has characters similar to the one just finished playing, drag-n-drop support for copying/moving files directly from the play-list in local storages, etc).
*. Removed "redo" button from the main tool-bar.
*. Now uses the ffmpeg 0.6 or higher by default.
*. Preview button, progress bar and few other layout clean-ups to make it look more simpler and "easy to understand" ... are just a few to mention.
While I checked it wasn't yet available through the Kubuntu PPA (backports) but you can add the PPA so when they do, you'll be able to install Amarok 2.4.2 Beta 1 in both Kubuntu 11.04 and Ubuntu 11.04 Natty Narwhal easily.
To do that, open the Terminal and enter the below commands.
sudo add-apt-repository ppa:kubuntu-ppa/backportsRemember, this is still in its beta stage... so may not be the best of Amarok, yet :).
sudo apt-get update
sudo apt-get install amarok