It's too early to say really.
But most likely yes.
The server needs to have access to the configuation data from all the addons to correctly simulate things.
However, depending on how the new addon verification system it might be possible to remove some texture data and stuff like that from the dedicated server.
Currently those are needed on the server to make sure the client is using the same files.
But really, 3GB isn't much and setting up server isn't something you do every day usually.
3 gig is not much get reall dude its a lot if yo rent a server and pay for 4 gig storage .This sucks big time and they should have a solution for running dedicated server .
But yes we should all wait for demo or game release now ppl do to much shitchat
blah