As I wrote earlier, the biggest problem in the identity 2.0 space is the absence of trustworthy public Identity Providers. I called for a trust framework that would enable differentiation in trust levels for identity providers. Of course that requires some major party to define the standards.
There is some great news about the development of a standard trust framework for identity providers. Initiated by the US Government the Open Trust Framework for Open Government was formed. In a White Paper the methods are described.
There are other initiatives, like the Dutch OpenIDPlus. Let's just hope that these initiatives will converge into an interoperable international standard.