the shuffle algorithm would have to go through on a second pass and "de-cluster" any songs from same artists/albums/whatever.

The first post I ever made here was to request this feature. In the end I "beat the system" by setting up a complex series of playlists that achieves this. (which only goes to show how flexable the playlist system is on the Empeg). One thing the Empeg guys may want to think about is how average consumers will react to this "pure" radomization in their other products. I'd guess that most aren't going to care whether the process is totally random or not, they'll want something closer to what you just described.