I really, really hope this catches on and gets built into browsers...
Until this incident DigiNotar seemed trustworthy.
This project is in its infancy, so get involved, set up a Notary, contribute on GitHub.
This is not the common case. There was a very similar incident with Comodo in March, and they weren't removed. This is because Comodo certifies some non-negligible portion of the internet (between 1/4 and 1/5th of certificates), and so removing them would break a lot of things.
The same is true for VeriSign, Thawte, Comodo RAs, Geotrust, Equifax, etc...
I don't trust any of these parties, and yet I kept them in my trust DB for years, because without them the internet was unusable.
What Convergence aims to do is make trust agility even easier than it was for DigiNotar, which itself was unusually simple for the CA model. It also aims to invert the trust relationship, and put trust decisions fully in the hands of the client.
Right now, I trust the browser/OS vendors with the ability to black-list individual CAs (or white-list, as the case may be). In the "trust agility" model, I just have to choose somebody else I trust, right?
Maybe as a technical person who spends time in the security world, I can figure out who that should be, but isn't the average person going to find themselves in the same situation (trusting the browser/OS provider)?
Perhaps the better way to phrase this question is thus: How does this prevent 1/4th of the SSL Internet from going down when Comodo gets hacked?
Trust agility ensures that clients have the ability to make these trust decisions easily. A client does not necessarily have to be a user, it could still be the browser/OS vendors. For details on how Convergence works, in order to answer your question of how it prevents 1/4th of the SSL internet from going down when Comodo gets hacked, the best reference is (unfortunately) still the presentation: http://www.youtube.com/watch?v=Z7Wl2FW2TcA
Thanks for taking the time to educate me.