A concept which causes implementers with a mind set similar to that of WardCunningham to discover ways to make a structure, an object or a process into one more useful or more fitting for the tasks it was meant to fulfill.
This is a phrase Ward uses on many occasions to explain something not yet explained or not having a name, but one which when named or explained is found to be an obvious part or extension of the thing wanting.
It might be this very want that drives inventors forward and awakens them in the middle of the night, or comes to them in a flash of inspiration when they are otherwise occupied.
According to some, it appears wiki wants to be a mess ;-)
I'll just posit, without references, that what the wiki wants to be is the GlassBeadGame.
Perhaps WhatItWantsToBe is WhatItIs. (in the WikiNow)