There's some stuff in there that was from Ghost21 and is known to be comlete bullshit, like Honsu and 'Little' Horus.
My personal hope is a re-worked book that gives plenty of options, but leaves the player with the ability to freely theme the army the way they see fit. (ie: if you choose IW's, you should still have the option open for berserkers since a number of grand companies do have such units!)
No more silly mark restrictions like if take an HQ with MoK, you can no longer access any Slaaneshii units either please. Perhaps I want my army to represent the classic confrontation between the World Eaters & Emp's Children that led to Kharn's famous 'betrayal' and the breaking up of his legion?!
I also hope that chaos marines keep Lesser Daemons, but gain the option to mark them. So for example, adding the MoK might give +1A + furious charge? MoS could give +1I + rending and so on...
Worst possible thing GW could do would be to give chaos marines '6th edition Daemons' and then leave us poor proper Daemon players out in the cold, forced to use crappier & much more costly versions of the same fething unit/s!
(or else GW will be forced to release a new Daemon codex within 4-8 months to bring us into line like what happened with TK's/VC's in Fantasy)
Hopefully GW do chaos the proper justice this time 'round, otherwise I'm going back to my 3.5 codex!