Marc Canter gets a lot of flack and I can't understand why. In the talk above he presents his vision for Persona Editor, something he's been working on for the last 5 years. While he talks about it I'm thinking its a outline with static data or dynamic data. The dynamic data is actually like a xpath or better still a xpointer to a node or collection of nodes. So for example Marc uses a example where he aggregates 3 of his blogs into one outline which he calls all his blogs. Where it gets confusing is once you create these outlines, they can feed and inform other structures such as widgets, dashboards, pages, etc which are static. But it can also inform dynamic structures such as open social and apis which allow writes (aka 2way api).
So in the blog example, you could define the blogs and then write them into something like Facebook or Blogger. The identity stuff is even more mind blowing and as the Q&A's point out there are some seriously scary privacy concerns to be worked out. So as a summary its a really good idea and I do wish someone would create it. I'm actually thinking Xpointer could actually really make this whole thing work too. It strikes me as something I could/would use and it would help me bring together abstract pieces of data around the web and locally. If it does what I'm thinking correctly, I could wire up Tomboy notes with Persona Editor and make it inform a Basecamp whiteboard or the same in reverse. Now that would be powerful.