I really loved the way amarok 1.4 was handling dynamic playlists.
This should bring back some of the old behaviour.
The script submits all artists in your playlist to http://www.tastekid.com, retrievs a list of similar ones and then fills your playlist with random tracks of the suggested artists.
Currently the number of tracks in the playlist is hardcoded to 10.
If you want to change the music style, delete the songs in your playlist, add 1 or 2 songs and play the first one. The script will then fill up the playlist.
I hope you'll like this.