In the future, such a process should be made more formalized I think (as we get bigger and bigger, it is harder and harder to just chat with everyone and then make it so), and quite likely the ArbCom (who, after all, ultimately make decisions about what "counts" as policy through their enforcement of it) should be the ones certifying.
So you're suggesting that ArbCom have a role in policy making similar to the role Bureaucrats have in RfAs? They come along after all the discussion and determine if a consensus exists? I like that idea, it's very easy to implement and would solve quite a lot of the confusion that almost always surrounds changes in policy.
Now, the question is, how do we decide about changing the policy about changing policy? This might be a good example of a time when it's best for a GodKing to step in...