What rolls out on day-one with more than 300 million users and nearly a BILLION authentications per day?

The new Windows Live ID, that's what. And that's exactly what happened, while you were using it and going about your daily business.

Microsoft's completed the roll-out of Windows LiveID to replace its Passport network infrastructure. It was all happening behind the scenes recently, and the next steps are for Microsoft and its partners to start rolling out some of the new technologies - some of which you can see and some of which is under the covers - to show off and leverage the new service.

"You'll start to see the new sign-in experience and all the goodness within a few weeks when we light up some partners," said Trevin Chow, Lead Program Manager on the Windows LiveID team.

So, what exactly is LiveID?

Well, you can read a whitepaper that was recently published to get all the salient details, but basically it's a new component in the Identity Metasystem that replaces Passport. It will eventually support both self-issued and third-party managed/issued InfoCards as credentials, and a SDK will be available.

What this all means is that Passport has grown up, and control of personal information will be more and more in the hands of the end users. In the future, Live ID will leverage InfoCards, which means more individual control of the claims used to identify users to online apps. Participation in the Identity Metasystem and following it's governing standards - the Laws of Identity - mean end users can leverage a centralized service but still maintain control over - and make decisions about - what specific information is sent to what services.

It's good news. Check out http://login.live.com - you'll notice the new footer on the signin section.