HTTP/2 support via Servlet 4 is one of the most significant changes coming in Java EE 8. The Servlet 4 specification is now gearing up for it's first early draft. The intent is to publish the early draft by JavaOne 2015. If you have an interest in Servlet 4, this is a perfect time to get involved in helping shape the draft. The two items specification lead Ed Burns has in his mind at the bare minimum for inclusion into the early draft includes:

Support for HTTP/2 server push.

A decision to pursue or deliberately ignore the Reactive Streams concept.

Any open issues on the mailing list at the moment.