At the time the Cloudflare blog post “ECDSA: The digital signature algorithm of a better internet” was authored, Cloudflare was apparently one of "fewer than fifty" users of ECDSA certificates on the web. It seems they have since stopped (via ssllabs.com test).
I briefly surveyed several other major web properties using that tool (Google, Yahoo, Microsoft, Facebook, Amazon, Tumblr). Only Google seems to offer an EC key and ECDSA suites.
When I test locally, though (with cipherscan or
openssl s_client -connect google.com:443 -cipher ECDHE-ECDSA-AES256-GCM-SHA384), I seem unable to handshake ("no peer certificate available").
Is anyone able to connect to Google (or another popular site) using an ECDSA ciphersuite?