Having some user-parameters set through emplode for shuffle would be great. Some items I can think of right now:
Don't repeat artist for at least [x] tracks (or [xx] minutes)
This would make it so you would not get two songs by the same artistwithin the time-period or song-selection range desired. If I want a true large-scale shuffle, then I don't want to repeat an artist within a couple of songs.
Don't play multiple selections from same source for at least [x] tracks or [xx] minutes
Similar to above. This allows you to not have a limitation on artist, but allows you to do it for their albums. You can also have a similar option for "nested playlists" as well. This way it won't affect the playlist you're currently playing, only ones below it (this allows you to play a large top level list including lots of smaller ones).
Of course these settings should be ignored by the player whenever it gets into a condition where it cannot choose any content that falls outside the scope of the rule.
I'm sure people can think up a few more good ideas along these lines or other mods to shuffle that would work well as emplode-level options.
Bruno