In a previous entry, I described the many players that were at the recent Internet Identity Workshop. Of note were LID, OpenID, and i-names, as they were all seeking interoperability of URL-based identity systems via YADIS (a group that was kicked off by Johannes Ernst of NetMesh). The work of the YADIS group is now even more significant, as VeriSign's PIP works on OpenID, and is therefore YADIS-"compliant." PIP is free and enables cross-site sign on. And since it works with YADIS, its not simply limited to OpenID (or LiveJournal) sites.
URL-based identity has been steadily gaining ground since the mid-point of 2005, and this VeriSign release would seem to signal that some very big boys are throwing their weight behind something. As VeriSign builds out its "blogosphere" strategy, it has made the crucial step of realizing that "identity is center" -- i.e., that it will enable future services and applications that could not be achieved without identity infrastructure.
This is obviously significant for digital identity, as it moves out of of the enterprise IT realm and into the end-user space. How will all of this play with the other players in the "user-centric" space (SXIP, InfoCards, etc.)? That remains to be seen.