The paper noted a few significant variances, including the inclusion of SoapProtocol in WindowsLonghorn, and MozillaTechnology of Html based syntax (Soap object has to be explicitly created).
"contrast" is an apropos word -- these are apples-and-oranges comparisons if I've ever seen them. Gecko vs Avalon? XPCOM and .NET? About the only comparable technologies are XAML and XUL