It's too bad, it sounds like a very good idea.
[kinda frustrating that the solution to many of these issues is sitting here at the bottom of the thread!]
Also how does this affect SSL certificiate "pinning" as implemented in Chrome? I guess it doesn't since even if you have a pinned cert for a specific domain Chrome will still verify the trustworthiness of the CA that signed it?
TACK is just a proposed standard right now; I have no idea where it's going. But it's a good band-aid on the existing CA system.
Second, the protocol and the code need to be independently reviewed. This hasn't happened as of yet, but I am sure will if the popularity of Convergence increases. I'd be willing to give it a go at some point.
Third, we need a good-enough infrastructure to start with. SSL Labs (which I run at Qualys) sponsors Convergence by providing 4 notary servers (2 in the US, 2 in Europe). These notaries are installed by default, so you could say that the infrastructure is decent (at the current level of usage).
Finally, we need to have the technology available in all major browsers, at the very least pre-installed and available as an option, but -- ideally -- fully integrated ("This looks like a self-signed certificate; please wait for a moment while we verify that you are not under an attack"). A big problem for adoption is that browsers are lacking APIs for this type of work.
Thanks
http://www.imperialviolet.org/2011/09/07/convergence.html
The reasoning is solid, unfortunately.
What's important is that they give the choice -- not just in a tucked away settings pane or whatever, but actually flash the question in the user's face in a meaningful way. If search engine monopolies are important enough to add "friction" to user interaction, then I'd say CA oligopolies are at least doubly so. The conflict of interest factor isn't present in the case of CAs, because, AFAIK google doesn't run any themselves (yet), but I think its still very important to give users the choice.
I also want to point out that Google runs all kinds of infrastructural nodes all up and down the internet's stack. They have no problem pioneering high-performance DNS to move the web forward, and they even are running their own fiber optic network, for crying out loud. They're huge on promoting IPv6 adoption, (mainly because it will remove any significant cap on the internet's (and thus their) growth). I think they can handle a few SSL notaries.
But security behind the scenes doesn't contribute to a palpably sexy image of the web in the masses' minds, so it doesn't really help google's bottom line enough for them to care. Kind of like how while their "speed" initiative complete with JSCDNs is terrible for privacy (third party resources sending referrers to Google upon fetching), it helps to make the web seem like a more serious platform in the subconscious minds of users by increasing performance.