I think as well that dtp would be a good choice - at least here where I live.
I'm in the official Drakensang forum - which will also be published by dtp - and I must say that they have quite a friendly athmosphere there.
I have met a few dtp members on a roleplaying games convention, the "FeenCon" in Bad Godesberg, part of Bonn, former capital of Germany, and had quite long chats with them - regarding the evelopment of Drakensang and the "Realms of Arcania" games.
They seem to actively support fan-sites and are generally quite positive - at least that's my very personal impression.
Personally, I would be glad if dtp and Larian worked together, but I must admit that I know next to nothing about how dtp behaves internationally.
Okay, that sounds really good 'cos publishers/developers who've these "holier than thou" or "sod-off" attitudes are darn annoying.
Generally quite positive? That's great.
About the international thing: I've got no idea either. Larian better make sure that said publisher gets this right. So far, found an interesting article about Anaconda:
http://www.gameboomers.com/interviews/anaconda.htm I'm talking about "all over the world", because most of our future games will be published worldwide by us. That means that we will be the actual publisher, and we will give the license to put the game on the market to a local publisher. To keep the players' focus on what we are doing, the new label will be on any adventure (and, in the future RPG as well) we publish.
Whether that's still their strategy, I don't know.