Yeah, and I'm also hoping they will gravitate toward more "standard" interfaces like you touched on at the end there.
With the help of Let's Encrypt and through some cooperation, we could make easily "pluggable" SSL cert providers where you can choose who you want with the click of a button.
I think it's fairly likely we'll see a number of CAs adding ACME support at some point. Judging by participation on the ACME mailing list, there seems to be interest from (at the very least) DigiCert, Entrust and cough StartSSL. I guess most of them will want to wait for the standardization process to finish before announcing any plans.
With the help of Let's Encrypt and through some cooperation, we could make easily "pluggable" SSL cert providers where you can choose who you want with the click of a button.