Sisters are here to stay, Templar's get their own codex and Apoc insights here:

From Warseer's Mauler

Apocalypse
Apoc is seen by the GW studio as a toolkit for massive games rather than a rigid framework, leaning towards making big games easier to organise and play rather than sticking to the background setting. The Allies matrix in the 40k rulebook with "Come the Apocalypse" is the truth; in Apoc you can ally with whichever faction you like. Formations are in there to give players a direction to go for with their collection: if you've got two Predators, pick up the Apoc book and are unsure about what models to get next (I'm paraphrasing here and I didn't pick up the Apoc book myself today) then leafing through the Imperial formations you can pick up one more Predator and get bonus rules for the 3x Predator formation, whatever it's called. Formations don't have points values as they're not units in the same vein as the core rulebook & codices, they're mainly there to provide bonus rules if you have groups of specific models and make things more interesting. The guys got the point across that if you don't like a particular rule you can just leave it out; if you don't need a particular tool in your toolkit you're not obliged to use it. Master Of Disaster which originally had a Viking helmet to pass around each turn to identify the Master) is wrecking massive chunks of table? Don't use it. Finest Hour? Optional. It's all there to be used as we see fit, it's even less of a tourney focused expansion and is basically a guide on arranging and playing oversize games with mates.
WarZone Books
War Zone books for Apoc will be more like mini-Imperial Armour books than supplements and will include new scenarios, unit datasheets, rules & historic background, orders of battle and timeline maps. The studio will use them to pick significant battles from the history of 40k (like the Battles For Armageddon) and flesh them out in detail along with rulesets for players to enact them.

Sisters and Templars
SISTERS OF BATTLE/BLACK TEMPLARS will get attention and are not in line to be dropped at this time.I spoke to Jervis Johnson and asked him myself and he said "Every army is getting worked on and will be updated in time." But obviously in true GW fashion he couldn't say when or if it would be via codex or supp.

From Enigwolf on Dakka
 I attended all of the Design sessions and because there weren't many people around, I manage to have very good, long conversions with Phil Kelly, Jervis Johnson, Guy Haley, and Jes Goodwin. I asked almost all of them about SoBs, and from the sounds of it it's not in the pipeline anytime soon. However, Phil Kelly has expressed interest in it, although he really wants to work on the IG 'dex because there's a certain "human" element to it missing from all the other races. He also mentioned that there are 3 Citadel Designers who have full SoB armies as their main army, and reassured me that they're still around. It's apparently also hard to "get rid" of a dex's contents once introduced, so no fear of Codex: Black Templars, etc. becoming a supplement. I prodded him more about how Witchhunter and Daemonhunters became Codex: GK, and he told me he wasn't involved in that, but it was an oddity within the office. 
Oh yeah, one last thing about the Sisters of Battle. According to Phil Kelly, the reason why they never got plastic minis was because they couldn't be plastic moulded by the current process. He wasn't really sure what the issue was, but there was something about the sculpt which meant that it could only be cast in metal. Presumably this led to declining SoB sales and a lack of development in them as a result.



Sisters are my favorite army, even though the new White Dwarf nerfed them.  I still have a beautiful army and the figures, specifically the Seraphim, are among the best GW ever produced.

Loken