The main part of this (split /resources up into library and non-library directories) has been done. Other parts (update libraries to most recent versions after testing) are done from time to time anyway – the preparatory testing for the jQuery 1.8.x -> 1.11.x work has been going on for months now, for instance – and moving our internal libraries that might be of use to others out of the MW core repo and into their own repo seems like a no-brainer.
