JBoss Fuse 6.1 is running on top of Apache Karaf which is an OSGi only container. So whatever you run in JBoss Fuse 6.1, is deployed and running as OSGi bundles.
We are working on making Fuse Fabric polycontainer, so you can run it on any kind of container you want, such as Apache Tomcat, JBoss Wildfly, Docker, VertX, DropWizard, standalone Java etc. That work is ongoing in the community version of JBoss Fuse which is the fabric8 project - http://fabric8.io/
So to answer your questions, yes you would need OSGi. But you do not need to use OSGi, you can use plain Camel, and deploy it using Spring or OSGi blueprint. Or use WAR files.
But in the future you can choose another container, instead of it being Apache Karaf.