Big news for Internet interoperability. Yahoo! announced its plans to start a public beta for OpenID support as soon as January 30.

OpenID is an open identity management system that currently allows about 160 million users to use a single signon to access more than 10,000 web services and sites that currently support it.

Yahoo!’s announcement means its 280 million users could become OpenID users almost triplicating the current user base, another significant push for this initiative that already counts Microsoft, AOL and other big players among its backers.

OpenID support was scheduled for Firefox 3 but seems it won’t make it. Not that OpenID requires some special help from any browser, but it can certainly help a better experience. In the meantime Firefox extensions like Appalachian and VeriSign’s SeatBelt provide some sort of OpenID support to ease the authentication process already.