Kirk Allen Evans has a great posting about the different components in .Net Framework 3.0 in which he describes .Net Framework 3.0 as an additive release to .Net Framework 2.0, adding WF (Workflow Foundation formerly known as WinOE), WPF (Windows Presentation Foundation formerly known as Avalon), WCF (Windows Communication Foundation formerly known as Indigo and WCS(Windows CardSpace formerly known as InfoCard), ... Also take a look at the original post from Somasegar about .Net Framework 3.0.
I think this name change will cause a lot of confusion - you have the .Net compiler 2.0 which works with the .Net Framework 3.0 ...Mmmm - let's vote for keeping WinFX.
After reading the feedback from Brad Abrams in Towards .Net Framework 3.0 as well as Even More on .Net Framework 3.0 I kind of understand the reasoning behind this all. For some more interesting background information about the strategy behind .Net Framework 3.0, take a look at the posting from Joe Wilcox - .Net puts on weight.
There also is a new website available to host available content about NetFX3 - http://www.netfx3.com/
P.S. I also have to admit that I did not recognize the WCS acronym at first, ... I always dismissed InfoCard as something that infrastructure or IT Pro should care about not developers... maybe I have to catch up on this new stuff as well.