Wow. A long thread... That in itself should tell someone up there that this is something people take seriously.
Anyway, like so many others I found this thread after i upgraded to iTunes 11 and became upset.
For all the people offering solutions I have only this to say: shuffling is not a solution for people missing DJ. Shuffling existed already in previous versions, and it solves a different problem. Anyone who have been using DJ only to get their tunes shuffled have not really understood what DJ can be used for, and for these people shuffle will work just as well, as it also did in 10.
Next is what I assume is the replacement for DJ, but it solves one half of what DJ does, but not the other. Next lets you see what will be played, but don't give you the control that DJ had. (Not to mention how clunky the interface to Next felt for me, being used to DJ).
The points of DJ is that the music selection was *not* random, nor was it a shuffle. It is/was a weighted random. Shuffle is what you do with a deck of cards. Each card shows up exactly once, in some random order.
A pure random function will give you a distribution that is random, and can repeat things.
DJ let you both do random selections with weighting, giving preferences to song you like, and also let you change the *planned* playlist. You can reorder the planned playlist while it is playing. Add songs to play next, or at the end of the current list, remove songs, and extend it way beyond the programmed list. DJ simply keeps a playlist of a certain length. When it is currently short, DJ will pick songs to add, based on the rules it has. If the list is longer, DJ will just keep playing through the list until it becomes shorter. And with voting, you can also have it automatically reorder what is currently on the list dynamically.
To claim that shuffle, in any form, can replace this is a joke.
Next is somewhat closer to DJ in that it lets you have a list of upcoming songs, but it totally lacks the functionality of DJ for how to pick which songs to add. Instead it has just two stupid modes. 1) Add the next song in the current selection (be that artist, album, genre, or whatnot) 2) Add a random song in the current selection.
Neither is obviously any good if the DJ functionality is what you want.
Not to mention that having the last few songs that played still in the list is sometimes very good, as you might realize you want to check what that song was that you just heard.
(Happily downgraded my MAC to 10.7 now)