I missed this when it came out last month at the Interop event in Las Vegas. Bob Muglia announced that the specs for Information Card have been added to the Open Specification Promise, and there are now several new open source projects set up to deliver code for Relying Party implementations in PHP and Java. In addition, there was an infocard interop connect-a-thon, basically a get together among various imeplementors of the specs to verify that everything works together as envisioned. Previously, Kevin Miller delivered a FireFox add-in that does InfoCard.
What does this mean? This means that (a) websites based in Java or PHP can accept Information Cards for user identity (of course it is already pretty simple for an ASP.NET based web app to accept an InfoCard identity), and (b) users who surf the web with FF can use InfoCards as well.
This is all really good news for Interop in the identity space!