Another way to think about it would be to have your central PubSub server (e.g., adampisoni.com) subscribe to Flickr, and essentially act as a proxy --- you give yourself permissions to your entire Flickr stream, and then choose who gets permissions based on your central roster. I still think the caveat above applies, though.
Right this solves who can subscribe to KNOW ABOUT my flickr stream, but that list of people is fundamentally the same as those I want permission to SEE those pictures. It's a shame I have to maintain those lists separately. I agree that in many places you want those permissions to be separate, but in practice, non-power users don't want to maintain many different sets of permissions. ie, most of us only have one group we think of as our family. OpenSocial and other such (ill conceived efforts) are trying to solve this very issue precisely because it is so obvious.
thanks, adam
