Like the AOL announcement of roughly the same thing in February of last year, the key question is whether Yahoo! will do anything substantive with OpenID or whether, like the AOL announcement, this will just be window dressing to legitimize advocates of OpenID. AOL's support for OpenID appears to have resulted in little more.
Though there's every reason to hope that today's Yahoo! announcement will lead to ongoing, meaningful advocacy of OpenID by the company and then a future wherein Yahoo! sites accept OpenID from other providers - there's also plenty of reason to be concerned that neither will occur and that Yahoo! interests are really only served by spreading the use of Yahoo! ID further around the web.
Nothing but a few information pages are live at Yahoo! yet, though the announcement went out a few hours ago. Those pages say that users will need to enable OpenID for their Yahoo! accounts; there's no info I can find on how to do that and other sites say they can't find an OpenID server when I try to use my Yahoo! ID that way. Silly me, nothing will be live until the last day of January it turns out.
Far more is possible
There's no information about what a Yahoo! OpenID will look like, either. Will it just be a dumb login or will the company offer important functionality like multiple personas (for privacy and user control), search friendly microformats and anti-phishing technology? There's a wide variety of ways to implement OpenID. I'd recommend you check out the site SpreadOpenID for a feature comparison of a large number of OpenID providers. Just authenticating OpenID is only the beginning, there's a wide range of features offered by various vendors too.
Public legitimacy and user numbers are great for the OpenID movement to receive from Yahoo! but I hope they will also contribute a significant amount of money. It sure seems to me that the whole thing could use some dedicated staff in order to put some meat on the bones.
What are Yahoo's interests?
One way to look at today's announcement is that Yahoo! will now know what other services its users use around the web and big yellow and purple buttons will be spread hither and yon. Sounds great for Yahoo! but if you've chosen another OpenID provider who better satisfies your needs - that doesn't mean much to Yahoo! right now.
What incentive does Yahoo! have to take the next step and offer full support to OpenID in general? Not much right now. In theory that could lead to access to user information from a wider number of users from other communities but when you're at the top of the hill with 248 million users that might not seem so important.
In theory if Google were to start accepting OpenID logins from Yahoo! users then the floodgates would open and Yahoo! would have to return the favor - but I don't know if we should hold our breath. Google has opened up to any OpenID login on commenting for Blogger but we'll see how much further that goes.
What's needed next
As a peripheral observer of the OpenID movement I probably ought not be so bold as to offer my suggestions for what steps should be taken next - today's announcement really is a big win for the OpenID community - but I'm an impatient blogger so I am going to do just that.
There needs to be a comprehensive campaign of public education about the value of OpenID in general. If Yahoo! would communicate with its users about these matters in a high-profile way that would be great. How many AOL users know they have an OpenID? Not very many.
Yahoo! should accept inbound OpenID from other providers. Have you seen the way that Basecamp and Ma.gnolia allow users to associate an OpenID with their in-house accounts? That could be a good model for Yahoo! to follow. If OpenID is about openness and not just about extending your own brand elsewhere, something like that has to happen.
Some of these major vendors need to put some money on the table. Presumably there are Yahoo! staff focused on OpenID and related matters, but neutral third parties need to be funded to move the entire agenda forward. I'm sure this is in the works but it's very important.
The pace of OpenID's advance is encouraging by some standards - 3 years ago effectively no one had heard of it, two years ago it was a pipe dream and one year ago the ball started rolling. This is the internet, though, and three years ago YouTube didn't exist. No one would cheer for the progress of online video today if it were crawling forward the way OpenID has. The benefits of online video are clearly communicated and there is money on the table, though.
OpenID is a matter of usability, data portability, user rights and will someday be a competitive necessity for vendors if implemented right. Today's announcement is good news, but let's not throw too big a party yet.