Google has been dabbling with OpenID for some time with its Blogger platform (and Brad Fitzpatrick, the creator of OpenID, is now a Google employee).
Yahoo also announced support for OpenID earlier this month, which more than tripled the number of OpenID accounts to 350 million. 10,000 websites now accept OpenID accounts for login.
All of the newcomers, along with Yahoo, have joined OpenID’s corporate board and, we assume, will be making their user accounts OpenID-compatible. But it’s not clear that any of them are in a hurry to become a “relying party” (allowing users with third party OpenIDs to log in to their sites). OpenID looks like it’s going to be a winner, so big companies making their user accounts OpenID compatible is a good hedge. Everyone, of course, wants to be an ID issuer, since they get to “own” the user. Less attractive is allowing users from other sites to log into your services, so don’t expect that functionality to come for some time.