I must say this is the fastest, most stable and flexible music player and I love its client-server infrastructure.
That said, I use media monkey sometimes because of a plug that queries last.fm for what is playing and from the results it does searches on its local library and either automatically adds or suggests what kind of music to play next.
This kind of feature would be marvelous especially when listening at work or at a party or simply a set and forget. Querying last.fm and perhaps returning suggestions below the lyrics bar on the right side and perhaps an option to automatically add X amount of songs from the suggestion to the current playlist.
This kind of feature would be much appreciated.