I've heard a /lot/ of rumors lately concerning the next book and the team for fantasy, some people are saying Phil Kelly is the new head of the WHFB team. If that is the case I would put my money on Dwarves being next. Kelly wrote the VC book and is a Vampire Counts player, which is the army that is currently losing primarily to dwarves (In the shooting phase specifically).
Also concerning the Wood Elves / Brits: I'm also a Wood Elf player and have heard a few things about them in my area and on the Asrai forums, primarily three things:
1. WE are going without a book until 9th and being dropped as an army (Doubtful)
2. Brits and Wood Elves are being combined into one army (Also Doubtful)
3. The WE arnt getting a book for at least a year since they are still a technically 'viable' army if you spend a fortune on Treekin and Eternal Guard as well as the fact that they don't sell very well compared to the other armies. (Yeahhh that is probably it)
Brits, well all I've heard is complaints about how annoying that charge formation of theirs is and that people hope its gone next book lol.