Its definitely an eventual consistency kind of model.

There was some attempts at change review (called "pending changes") that is used on very continous articles, but it never really scaled that well. I think its more popular on german wikipedia.

Wikipedia is so dominant that it has kind of smoothered all alternative models. Personally i feel like its kind of like democracy: the worst system except for all the other systems. All things are transient though, i'm sure eventually someone will come up with something superior that will take over, just like wikipedia took over from encyclopedia briticana.