If theres one thing I have learned in the few short years I've been gaming its never to get involved in or even bother reading forum wish list discussions about what new army books should include. Most such discussions are painfully horrible... although I have to be honest and state that I did post a Dwarf wishlist on this blog a year or so ago, and it was... painfully horrible.
But sometimes such discussions are pretty good and I recently came across one on "Heros Gaming Blog" probably the best one I've read for a long while. I highly suggest High Elf players out there check it out.
It also offers some clues as to where the next Dwarf book might head. Although this, like High Elves, is a long way off. The web chatter pretty much confirms that the next three books out will be Bretonnians, Ogres and then Wood Elves.
With Orcs and Tomb Kings coming out so close together we can only hope that GW move just as quickly getting the others out as well. But as each new book will most likely come with a huge range of new miniatures it will take some time to get their production lines tooled up to cater for too many new books in a short time period.