He says:

Even a tech-savvy person like me has a hard time envisioning, never mind comparing, the interaction scenarios proposed by various identity schemes

I completely agree, and would add that nobody, not even the "insiders" really understand what consequences all the different proposed architectures have in terms of, say,

• who gets empowered and whose power diminishes
• how the attack vectors on those different architectures differ
• what governance structures are needed once any of this becomes a mass-market technology
• and so forth.

Which is why I think the Internet Identity Workshop put together by Kaliya Hamlin, Drummond Reed, Doc Searls and Phil Windley is such a good idea. If we all do our part, some real insights will come out of this workshop.