Conclusion

DAML-S is more complex than WSDL.
DAMLS-S gives a lot more details about how a process is composed of other process, what sequence they must execute, etc.
It's processes are akin to AI-planning operators.
Just-in-time service composition will be much more likely if services are described using DAML-S. Unfortunately that will require extra effort on the programmer's part (WSDL can be generated automatically).
DAML-S is sits righ between web-services (RPCs over HTTP) and the Semantic Web vision.