MS seem to be doing a good job of building it into IIS, Traffic Server has it, as does H2O, nghttp2 and others.
Google, FB, Twitter, Akamai have adapted their http daemons for it.
nginx has SPDY support so HTTP/2 should be forthcoming but I wonder if this will be the death of Apache - they didn't seem to be able to update the SPDY plugin to 2.4