You will be able to get one or more security tokens from one or more authentication providers and use them as you see fit. Each security token can have one or more claims. A claim is any information attribute associated with a particular identity. A claim could be a real name, a date of birth, a statement that you are over 21 years old -- anything. For any particular identity, you can supply as much information as you like, or no more than required, for a particular service. You might remain completely anonymous or go pseudo-anonymous.
Pseudo-anonymity allows you to stay anonymous (that is, not reveal your true identity) by using another identity to which a trusted third party attests. You could remain anonymous to a particular service as long as the service provider accepts the third party's attestation. For example, in most parts of the United States you have to be 21 years or older to buy alcohol. When you buy alcohol, the store doesn't care about your name or address (which is on your license); it only cares that the ID you are showing is truly yours and that you are older than 21. A pseudo-anonymous online ID might confirm that you are over 21 without revealing any other information about you, so you can buy alcohol over the Internet. What a great world it would be where you could reveal no more and no less about yourself than the information necessary to complete the transaction.
All of these new specifications and standards will allow us to build huge identity metasystems, where many disparate identity/authentication systems can be connected to create large circles of trust. These trust networks will include not only banks, manufacturers, and retailers, but also huge cloud services, including competing service providers, all of whom will be able to vouch (to varying degrees) for their users.
The upshot is that the boundaries created by the fact that every commercial Internet service today has its own, isolated authentication system will be removed. The user of one cloud service will be able to move seamlessly to another. An individual company will be able to offer a service to the cloud, and get different users from different clouds to their service. Even national identity systems, now separate, will be connected with each other and with the cloud. The Internet will be both more secure and more useful.
Yes, this vision has a way to go, but the protocols are already in place and in use by vendors who are already working on products that support this proposal. This is not a pipe dream. It is the culmination of decades of work on identity management, and it will be coming to a Web near you in the not so distant future.
I've updated my "Fix the Internet" paper (now in version 2.0) to reflect the role of these existing protocols and to offer a simpler alternative solution (called Solution No. 2) that can be implemented today without the need for any new protocols. You can download the updated draft here. Save the Internet!