Windows CardSpace Team Blog @ blogs.msdn.com - Finally !
CardSpace: Behind The Code - http://blogs.msdn.com/card/ ( what else could it be ;) )
Well I don't know if WPF / WF / WCF teams have a BLOG outside the netfx3.com domain , but now the CardSpace team has one , and the above is their "space".
Thinking of it, as opposed to the others, CardSpace is almost half product half technology ...
Why ? the concept is based on the use of public WS-* protocols, and the CardSpace was written from scratch, with disregard to the Microsoft "Product", for Linux and Mac by Novell , using plain simple C++ and TK for the GUI while the engine is using MONO ( as far as I know ! )