We are using Web Services in several applications, such as Search, and the Downloads page, as well as, MSDN. At this point most of these services "behind the scenes" and not publically exposed yet.

There is more infomartion here:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/MsComWsSDKProject/SDK/Introducing_the_Microsoft.com_Web_Service.asp