+1 to the adding the support for HTTP/2. I would personally like to see a few things happen before that though (which I've been putting some effort into as i can)
+ refactor http.client to cleanly separate transport from application protocol level
+ figure out some kind of adapter interface in order to facilitate swapping between 1.1 and 2 (This can start with a clean HTTP/1.1 interface)
+ full HTTP/1.1 support. Given (as i understand it) HTTP/2 is largely an extension of HTTP/1.1 it doesn't make much sense to me to implement the latter before the former.