Switchyard is actually at the top of "JBoss Fuse Service Works" (which is the new "JBoss SOA Plattform") as a framework for service-oriented applications.
Fuse provides Camel as the framework for integration that use the enterprise integration patterns (EIP), but doesn't offers the features like a SOA Plattform (like service registry or UDDI ...).
They are both ESBs but for different use case; one is for SOA and the other is for integration, and they're also based on different containers; Fuse Service Works has the JBoss EAP as container, an J2EE spec, and FUse is based on Karaf container, an OSGi 'spec'.
I hope i've helped you.