Catkiller - I've been concerned about the issue you're talking about since day one here (technically, before day one). It's why I've taken such a hardline stance here against things like the formation of the forum for people with real problems. Also why I voted against the deletion of Atomika's posts, even though I wasn't around during the peak of the problem to really argue a case for my vote.
I agree with whoever it was that said we shouldn't put all our eggs in one basket. I also agree with Catkiller that it's really important to be vigilant. I've seen takeovers far more insidiously than that officious bullcrap of MrMark's, and even used some of the same techniques myself when I was trying to get established at WrongPlanet a couple years ago.
The biggest forum drama messes happen when all the people in power have their emotions invested and clouding their judgement. (I can back this up with plenty of familiar examples if anyone cares.) So the system needs to be set up in such a way that there is always somebody likely to be uninvolved enough to be objective. We're already doing it to a degree by having the two webmasters, the admin who's not likely to be power hungry, and the world council for voting. But yeah - we do need to be careful.
Heck, maybe the constant influx of disgruntled WP members is a good thing, because it means some people will always have frustration over misuse of power forefront in their thoughts. Good for vigilance.