I just finished Grudge bearer and while the book is nothing special, it does mention some interesting things about dwarfes and their dark cousins.
As this book is written by Mr Thorpe i think it might hint at the further development those two races might take.
Warning very minor spoilers to follow.

Most interesting about dwarfes is the, imo, first mention of so-called "locomotives", which are engines used to transport cannons etc. into batlle. Possbile new warmachine perhaps? (in the far future).

Now chaos dwarfes have more info:
- earth shakker cannons are mentioned
- they still have magic users (priests of hashut)
- their elite regiment is called "immortals", which implies that the babylonian theme is still in use, as that was also the name of the bodyguard regiment of the persian kings.
- they have a giant walking warmachine, called the collosus

That's it, if anything of this finds it's way into future army books, i claim right of first mention