My opinion on this subject:

English Threads aren't a problem, but an english sub-Forum probably won't happen. We've already had a discussion about it not too long ago and agreed that Vvardenfell.info won't be able to build up a big enough english User Community.
You can find english Morrowind gamers on the official forums, and there also some more english forums aside of that. So there really isn't any reason to extra visit a german forum with an english sub-forum. Gothic is different, it's a german game after all, but it wouldn't make much sense for Morrowind.
Maybe my Co-Moderators and the webmaster see that a bit differently than I do.