re: MJ
I have no doubt he has 100's of unreleased songs in various states. Too, if he called someone up to collaborate I'm sure they would bring as much stuff as they could just to get a cut on one of his albums.
I haven't really been interested in those unreleased compilations they've put out since his death. They seem to mostly be from 2000 on, I think, and some question if it's really him on the songs anyway, even his family.
The other day I was in Wal-Mart and they recently put out a CD single:
http://www.walmart.com/ip/I-Just-Can-t-Stop-Loving-You-Walmart-Exclusive/20925480
The b-side is a demo. Not sure if it had been released before.
While looking for that, I saw that there will be a 3CD/1 DVD 25th Anniv Bad released in Sept.
Like Dr Dre right now. Detox has been going on for over a decade. I'm sure there are 100's of songs from that.
With a project like that, I wish he would release his finished album version, and then release all the other stuff. Like a Smile/Pet Sounds box or series, that would be cool that once (and if) he puts Detox out, then they started releasing everything by year. You would get everything he worked on in 2000, etc. For me, with a lot of these type of albums that involve a lot of collaboration, it seems they keep some songs that are weaker maybe because of who's on it, instead of choosing the best tracks.