I know i'm gona repeat a lot of ppl because this thing has been discussed more times ....
For me it wouldn't be such a big change but you could really earn a lot of users by making the player window xmms skin compatible ... or you could make a script that shows a simple player and playlist windows compatible with the winamp/xmms feel.
I know it's not the amarok way but I feel that amarok can be the best ... and making it only beautiful only by its complexity won't attract the mass of ppl .