At the conclusion of several days of immersion in the world of digital identity, I would ask the question: where are the people? Here's what I mean:
Most of the companies at Digital ID World don't seem to really care about linking identity to people. That is, they are content to have an identity with the appropriate attributes attached to it. Let me give an example: when you present your credentials to a web site to purchase something, they don't care about the meat attached to that identity, only that it has a proper credit card number and an address to which to ship the goods. The same is true for digital rights management (or, as Doc says: "digital restrictions for monopolies"). Digital rights management is about anything but people.
For most applications, the question of tying identity to people is relegated to a question of security. I want my identity secured, so that only I can use it. That's not an identity problem, its a security problem. Technology like passwords, smart cards, and biometrics are used to protect identities, which comes down to tying the identity to a particular person.
Now, consider some applications where we do want to tie identity to a body. Suppose, for example, that you want to set up a system to serve people with court documents online. Another example would be closing an online mortgage. Most of the examples I can come up with have a legal aspect. We want to tie the identity to a body because later we may need to take that body to court or arrest it on the basis of something that that body did with its identity.
Notice, as an aside, that digital certificates work very well in these kinds of scenarios, as long as the digital certificate has been carefully issued and protected (neither of which are great assumptions).
My most extreme thought in this direction is that the courts, at least criminal ones, are, in the abstract, a system for tying identity to a particular body. If you think of the attributes surrounding a perpetrator as an identity, courts are used to link that identity to a suspect (or body) so that they can be put in jail. Put that way, linking identity to a body is a very time consuming, expensive, and imperfect proposition in many cases.
That leads me to a conclusion that I've stated before: government has to be and will be in the identity business. Governments care more than most about tying identities to bodies than most and will act to ensure that its possible...eventually. Just don't hold your breath.