Paul or Derek would need to chime in on any actual plans.
However, there are some valid security concerns involved with tying your membership and thus your entire EE install into a system that is run on servers not directly under your control.
I’ve not looked at the complete details of how OpenID works but I have a read a few pieces by people who have. There are some real potential issues with the way it works. And any time you relinquish site access to something you aren’t fully in control of there is potential for very real security issues regardless of how well designed it is (and there are people of the opinion that OpenID is fundamentally flawed in its design).
In addition I have used a few sites that use OpenID accounts and created one of my own to play with. I found the process very confusing from a user standpoint. It quickly becomes unclear where your account actually is. Where is my password stored? Where do I go to change it? Why do I have two logins for some sites with OpenID but only one for others?
Other than being a current buzz word, I don’t personally feel that OpenID integration has much of anything going for it. EE has an incredible track record in terms of security. I would be extremely hesitant to mess with that.
Please note again that Derek or Paul would need to chime in to give an idea of what kind of plans they might have for EE and OpenID. The above is my opinion of the state of things not EllisLab canon.
Jamie