XSD:Any is Evil
We just received a WSDL from one of our business partners. The service had six operations with 12 messages defined. The problem was that each message referred to a data type of XSD:Any. Most java stacks and .NET see XSD:Any as simply data type Object.
Now you may ask what the problem is with XSD:Any - after all it produces an interface which is "loosely coupled". Well the problem is that it produces an interface which is totally useless for the consumer. If you are working with this service in Java, you will see Object Operation (Object arg1). The problem is that you have no idea about what data you need to send or what kind of return value you are going to get back. In this case, you must get in contact with the consumer to get detailed instructions. Doing this obviates the whole benefit of Service Orientation!!