Whenever I think about OpenID I feel it comes dangerously close to a walled garden. Jeff even had a post about this a while back:
http://www.codinghorror.com/blog/2007/06/avoiding-walled-gardens-on-the-internet.html
If everyone is forced to adhere to some universal internet sign-on policy it kind of defeats the freedom of the internet. Having to keep track of multiple usernames and passwords is a bit of a hassle but I don’t think this is the answer.
To quote Jeff from the article I mentioned “The lesson I take from this is that no matter how wonderful your walled garden is, it can’t compete with the public, open internet.”.