Change is inevitable, but with a little planning and a few key principles, you can minimize the impact that changes have on your WCF service consumers.
Adding MSMQ to your WCF-based service adds complexity, but any challenges from that complexity are greatly outweighed by the benefits.
Queues provide a useful isolation layer between a service and a caller (or vice-versa) and become a place for messages waiting to be processed.
The Windows Communication Foundation simplifies reliable messaging.
Windows Communication Foundation simplifies the creation of transactional services.
Don’t let the term, "governance" strike fear in your heart while planning your Service Oriented Architecture. You might already practice governance and don’t even know it. Now learn how to use governance to your advantage.
Use the Microsoft Managed Services Engine to manage the changes in your SOA.