http://msdn2.microsoft.com/en-us/windowsvista/aa904955.aspx

Now, we don't need to download Orcas CTP.

Extensions for WPF / WCP and Extensions for WF replace it.

http://www.microsoft.com/downloads/details.aspx?familyid=5D61409E-1FA3-48CF-8023-E8F38E709BA6&displaylang=en

http://www.microsoft.com/downloads/details.aspx?familyid=F54F5537-CC86-4BF5-AE44-F5A1E805680D&displaylang=en