Ben Laurie of The Bunker Secure Hosting has a provocative post about the two emerging (and that's important) leaders in user-centric identity: OpenID and CardSpace. He quite rightly points out that at present OpenID's:

popularity is entirely on the provider side. There are no consumers of note.

and that CardSpace:

appears to live in its own little world, supported only by Microsoft products

I think this is to be expected given that we are still in the early stages of both.

Where I find myself disagreeing with Ben, however, is with his conclusion about CardSpace:

So why does this make Cardspace like Passport? Well, the fear with Passport was that Microsoft would control all your identity. The end result was that Microsoft was the only serious consumer of Passport. When Cardspace is deployed such that all providers and consumers of identity are really the same entity, then all its alleged privacy advantages evaporate. As I have pointed out many times before, when consumers and providers collude, nothing is secret in Cardspace (and all other standard signature-based schemes). So, there’s no practical difference between Cardspace and Passport right now.

Ben's right about the implications for privacy when the those consuming identity information collude with those providing it but that's not an issue peculiar to CardSpace.

Even Microsoft would (and indeed does) agree that Passport was a failure due to the company's control of identity data, I think Ben doesn't tell the whole story. It wasn't just down to control of an individual's identity data. It was also due to the fact that Passport and Hailstorm were designed from the outset to wrest control of identity data from Microsoft's business partners and customers. The same can not be said of CardSpace and that's why I believe there is a difference between CardSpace and Passport. There are already examples, Otto in Germany springs to mind, of organisations other than Microsoft using CardSpace and, as I said, it's still early days.