On a tangent: one practice I'd genuinely like to see for security reasons (and which I'm surprised the CAs haven't proposed themselves, since it would make them twice as much money) is that major sites should always hold valid certs from two CAs, so that if a CA gets revoked it's just updating a file or even flipping a feature flag and certainly not signing up with a new CA. It would make sense to have two certs generated by different software, then. (It might also make sense, re abuse of power concerns, to present both certs and have browsers verify that a site has two valid certs from two organizationally-unrelated CAs. That way you can be significantly more confident that the certs aren't fraudulent.)
