The book will most likely not see any new units, but there will be a few more special characters added at least, including the famous Hisme Stoutheart. Overall, it will mostly be a major facelift with much improved layout and formatting (can't believe how much progress I've made on that front since early 2012) as well as some re-balancing (expect prices to go up). I would guess September, but I'm not promising anything.
Current Progress:Contents/credits - in progress
Society - done
History - done
Timeline - done
Geography - done
Bestiary - done
Special characters - done
Magic Items - done
Army list - done
Summary - done
Update 1: Lot of progress has been made already as you can see! I've done some major editing in their background section, so you should see a lot less repetition in the text compared to the old version, and every it much better laid out for easier reading.
The special characters will take a while though as they need a lot more fluff to fit a whole page, and their magic lore will probably be rewritten completely. The army list too needs to be re-done, since I'm using different templates for it in the newer books. Still, a mid-September release looks very much plausible now, if not sooner.
Update 2: Turns out "sooner" means "this weekend". Writing fluff for Halflings turned out to be surprisingly easy, meaning I now only have the army list left to do really. I will probably finish that part later today or tomorrow, so you can expect to see the new version on Sunday at least.