(I'd argue that changing the skin to vector is a
strategic decision by
WMF and cannot be overruled by local communities - but that's something
a system administrator has to decide.)
I'd say the system administrators will do as the foundation (board
perhaps? or some other organ) says.
Having different looks on different wikipedias is raising some
identity questions, but I'd say that the simple fact that right now
en.wiki looks in a way and smaller wikis look differently is a hint
that the problem is not that serious. I'm really curious about the
outcome of this discussion, be it here or not :)