You are absolutely right. Although I think it is undesirable to enable such a feature by default, as a technical user, I badly want it. I want browsers to cache

You are absolutely right. Although I think it is undesirable to enable such a feature by default, as a technical user, I badly want it. I want browsers to cache certificate public keys and alert me when they change. Note that Chrome's key pinning feature (http://www.imperialviolet.org/2011/05/04/pinning.html http://www.imperialviolet.org/2011/05/04/pinning.html) is a somewhat comparable idea, except the well-known key hashes are hard coded in Chrome and not user updateable.