OK, perhaps the Highlander reference is too obscure. But the point Mike Jones makes in this post is that OpenID and Cardspace can coexist just fine and Microsoft likes them both.
I would also point out that in this space that is far too much emphasis placed on symbolic actions like Microsoft joining the OpenID Foundation and far too little emphasis placed on what companies actually do, such as shipping Cardspace with every new version of Windows Vista.
Microsoft may or may not do great things with OpenID in the future. But they are shipping Cardspace now.