And, to complicate matters even more, as has already been hinted on, none of these guilds have any official status. Basically, in most cases, a group of fans got together (or even one fan grabbed a website domain and plunked a forum on it, invited his/her buddies and created an ad hoc community/guild, crudely spoken). Anybody can call themselves the So-and-So Guild.
As an example, right now there is a group calling themselves the Guild of Writers which has the domain guildofwriters.com. Suppose somebody else comes along and does not like what they are doing (say, theoretically, in the future this group of people forks off the "official" Cyan ideas to start a nudist camp URU, I emphasize: THEORETICALLY), then there is nothing to stop another group of like-minded people to grab the domain wearethetruewritersguild.org and call themselves The Guild of Writers as well.
Nothing is written in stone yet, and I for one am very curious to see how things will play out in the future. As long as none of these groups have official status, anything goes... until Cyan says otherwise.
Probably not helpful but that sums up the current (muddy) situation pretty well, I think
