Interesting, I used the same concept of putting "mood" playlists in parenthesis when I organized my music that way on my computer.

I really like the concept of "un-shuffling" around a song, but I'm worried about the player's behavior:

let's say you're at number 65 in your shuffled playlist, which is The Beta Band, and you unshuffle so that you can hear all of The Beta Band. When you hit the shuffle button again, does it:

1) shuffle in the same order as before
2) shuffle in a different order, BUT make sure that you won't hear songs 1-64 in the original order anytime soon, since you just heard them
3) neither

I've played around it and I'm pretty sure it doesn't do option 1, but I'm not positive.

PS. When you shuffle by "least often played", it seems like it doesn't necessarily play all "zero-played" songs first, but tries to generally put them in front according to some weighted algorithm...is this what's really happening?

...With software this powerful, I want to make sure I do the right amount of adjusting-myself-to-software vs. adjusting-software-to-my-preconceptions.