From CloudFlare's perspective we currently support SPDY for all customers and will support HTTP/2 once NGINX with it becomes available.
We are committed to support for new protocols for all customers. We've rolled out SPDY, IPv6, HSTS, HTTPS (free certs) for all and are close to adding DNSSEC and will add HTTP/2. We're not waiting for these things to gain traction.
To give you an idea of what we are doing and the impact take a look at this chart of SPDY deployment.
What about content push? Will CloudFlare only do passthrough of pushes from HTTP/2 servers, will it support extended HTTP/1.1 headers as described in https://news.ycombinator.com/item?id=9296526, or will it add content pushes based on parsing the HTML if optimizations are turned on?
We are committed to support for new protocols for all customers. We've rolled out SPDY, IPv6, HSTS, HTTPS (free certs) for all and are close to adding DNSSEC and will add HTTP/2. We're not waiting for these things to gain traction.
To give you an idea of what we are doing and the impact take a look at this chart of SPDY deployment.
http://w3techs.com/technologies/details/ce-spdy/all/all
There's a sudden increase in sites (a doubling) using SPDY. That's when CloudFlare have every single customer free HTTPS and SPDY.