As with all 40k info, Natfka has it covered first. September 22nd is the pre-order day so says he! So we should be seeing some previews of what there is to order come this weekend.
The trend for 6th edition has been these "limited edition" releases. Which are really not all that limited and not all that cool. I wonder what kind of "limited edition" crap they are going to peddle this time? The Interrogator Chaplain is pretty disappointing, but he only increased the cost of the box by a couple bucks.
To be fair, if they do a limited edition daemon prince or something, that would be cool. You really need a big, iconic model to make a special run on. Otherwise it's just kind of meh.