For good reason a lot of people are claiming a contract first approach in terms of Web Service design.
I think it makes perfect sense to use a sound vendor independent format to describe important resources like for instance Web Service interfaces.
But this approach is not limited to WSDL only. It applies to Business Process Execution Language (BPEL) as well as business processes are very valuable resources for every company. So if you have to model bunsiness processes for technologies like Microsoft Biztalk Server 2004 or BEA Weblogic Integration you might be good advised to use a BPEL first approach. Two tools that might help you are:
Cape Clear Orchestrator Beta. Both are Eclipse plug-ins and create plain BPEL 1.1 which in turn can be imported to the application of your choice.