honestly at this point, i think most people are using jquery with either jqueryui or bootstrap. Still its really sad to see such an established framework become EOL. Thank you Yahoo for all the work you've done on YUI.
Nowadays Angular is what killed jQuery for me (I still like to be able to use jqLite or jQuery if needed it though).
I guess that (regular CS) pattern means that the next big thing will be a lightweight library (React ?).