Hi, my name is Tariq Sharif and I am a program manager in the CardSpace team. After we released CardSpace V1 we received feedback from hobbyists, early technology adapters and site owners that getting/setting up a SSL certificate is hard and it is not needed for some set of their scenario and that this is blocking them from accepting information cards on their sites. Based on this feedback, the feature team decided to remove this requirement for the .Net Framework 3.5 release.
In order to invoke Cardspace from a page that does not have an SSL connection you need two updated components. First you will need to install an updated browser specific extension that will work at an HTTP site. You can download the IE extension from here or if you have IE7 you probably already have it as part of the October security update. Second you will need to install an updated version of Cardspace that does the right thing when a website, the relying party, does not have a certificate. Latest version of Cardspace can be downloaded as part of .Net Framework 3.5.
You can read more technical details about this new functionally here in this post that Ruchi made a couple of weeks ago. Please feel free to drop us any comments on this, as we are always looking for feedback to help us refine this emerging technology.