Not many people are aware of our commitments to ship WWSAPI to downlevel platforms. Nikola just sent out an email annoucing the availability of the RC bits for downlevel platforms: https://connect.microsoft.com/WNDP/Downloads/DownloadDetails.aspx?DownloadID=18901. There are bits for XP SP3, Windows 2003 SP2, Vista SP1 and Windows 2008 SP1.