This excellent article by Heinrich Gantenbein of Avanade examines a scenario where bridge technology really shines when connecting a new .NET app to an existing Java-based system.  At the Microsoft booth at JavaOne 2005, we had partner JNBridge demonstrating their JNBridge product, to great interest among many developers.  Other bridge products also work well.  Web services solves many problems but it is not the only answer.  It's good to have options.