How big a download will the update be?

One thing not mentioned in any of the update notices I've seen is how big a download the update will be. Will the update use the streaming technology that was boasted about during release? Have we already been downloading content as we play?

it will most likely what we have been doing so far with updates, load the client, and then it auto updates

As Wa$d said, you'll likely have to do a client update when they apply the patch - and then when you go to the relevant area's they will get updated and/or downloaded. ie say the way to the updated area is via a npc telepoter in Rankor Camp, the next time you visit Rankor camp you'll download the updated files and then when you zip off to the Sorrow's Furnace area's you will download all relevant files needed for those area's as you get to them.

Note - the npc teleport thing was just an illustration, don't take it as gospel