I’m pretty sure that when Yahoo decided to adopt OpenID, making it easier for users to switch to Google, was not on the list of benefits it had in mind.
Well, OpenId does make it easier for you to login to your Yahoo account and share information with trusted, third-party sites. That’s something that Google plans to take advantage of, by making it easier to set up a Google Account:
To make this process simpler, we’re now using an Internet standard called OpenID which is supported by several email providers, including Yahoo!…
I think it’s somewhat hypocritical that Google makes it soooo easy to sign up for Gmail et al, yet isn’t exactly setting the standard for making it easy for us to get our information back out of Google.