I'm looking forward to the GA books, maybe they are a little bit like the Index Books early 8th in 40k.
I wasn't very interested in warcry when the roumor was its only chaos warbands. I like the idea and the setting and most of all the rules. Whith the idea of only chaos and to become a varanguard, ist sounds more like a small board game to me, like the Khorne Arena Game a few years ago. There would not be much to add to a game like this.
I'm glad they added AoS factions, balanced or not. Those who want to play the game with only the chaos warbands can totally do so the basic game has a lot of options on its own, and those who don't like them have ton of other options to play the game. For me warcry is like a sandbox skirmish game. I can play the basic game or can create my own scenarios, campagnes, quests, stories and terrian. The lore is greate but there ist not very much of it, GW should add more to the books or the campagnes.
I hope they continue with the warband cards after GA books, really like them and think they are very useful ingame.