Even if one was added, I don't think .for would be best. Maybe something more generic. We now call them forums, but there are lots of other similar community type sites out there. In the past they have been called a discussion groups (usenet, yahoo), Bulletin Boards or BBS's, and intranets. Chats and IM are another form; and blogs and myspace/xanga type sites have become the newest social networking type sites. If you were going to separate for the long term, I think putting all the social networking media into a TLD that would work for all would be best. Again, .net works, and .soc wouldn't be bad either.