http://www.elderscrollsonline.com/en/news/post/2013/04/19/ask-us-anything-alliances-at-war

Newest AUA from the team, answering PvP-related questions. Trebuchets and ballistae. I can't freaking wait!

Liked the parts of the siege equipment and the resources. Now we have some information that Lumber Mills -Door Strength, Farms - Soldier Strength, and Mines - Wall Strength.

Awesomes! I totally want to specialise in seige machines.

"There are a few different ways you can detect sneaking opponents. For example, a player who’s sneaking is revealed upon taking damage. There are spells that can detect opponents who are trying to sneak around. It’s also important to remember that sneaking uses stamina, and you really don’t want to be out of stamina going into a battle."

This one is interesting. I take this as confirming that sneak will indeed make you invisible in PvP. Should make for some interesting dynamics, like having sentries running detect life spells at key chokepoints.

a few nice responses, nothing major but some more details on things we already know
always good to learn more about the game

Yep. I'm thinking that mines will be the priority, since you at least know where the doors are, and can be ready for them. Fragile walls means that you have to expect an attack anywhere. What's this 'soldier' thing about though? Will there be NPC guards at keeps?

EDIT: just saw this:
"Villages are Alliance-neutral. However, guards will patrol a town if your Alliance has captured the nearby keep."
So apparently yes. Not sure how valuable those'd be though. I'd rather PCs, but I guess a sword's a sword, whoever's swinging it.

Yes there are NPC guards that are in the keeps, villages, and patrolling around the area. So it seems that as long as you hold the farms near by the NPCs for your Alliance will be very strong.

I like the resource idea gets everyone involved in the process of battle .I look forward to see how it works out .

Hopefully the rewards are enough to stop zerg fests, I'm still pretty hopeful they'll remove this problem. It's a lot more fun for me to defend a keep than it is to take one.