A telling paragraph from an old article on connecting Microsoft Office applications with web services reveals why Sun has already lost web services battle.

Making implementation of Web services easy for VBA, Visual Basic 6.0, and Visual Studio .NET developers is Microsoft's key tactic to maintain its front-of-the pack status among today's Web service Gang of 2.5. When Sun delivers on its Sun ONE promises and Oracle releases its SOAP-enabled 9i Application Server sometime in 2002, there'll be fierce competition for developer attention between the expanded Gang of Four. I'm betting that new SOAP-based developer toolkits, such as that for Office XP, and on-time release of Visual Studio .NET will make Windows the primary platform for hosting and consuming commercial XML Web services.