After hearing news that Guilds will be able to control Holds in ESO, I was curious as to the approximate size of such a hold. Will is be the size of an Orc Stronghold, Castle/Fort, or will it be something like a Village similar to Riverwood or Falkreath?

Dont think we know the size yet but we do know we can upgrade them to be much stronger and have more guards and have more "things". We know that when patrolling guards are killed we will get a guild message telling us that they died and how many enemies were in the area.

I have a feeling it will be very similiar to Darkage of Camelot. In that game upgrading the keeps took time but made them so much better, Size wise i would say a level 5 keep was twice as big as a level 1 and level 10 was twice the size as a level 5. you could purchase many upgrades, counter seige equipment, guards, boiling oil over the doors, crafting stations, bind stones, guild vaults and so on.