I realize this is a bit of a late response :(.
We have been using the http://ws.apache.org/ns/synapse as the synapse configuration namespace, since synapse was graduated on to the WS project and we didn't want to introduce a configuration incompatibility because of becoming a new TLP, and with the new 2.0 release planned to be out, I am planning to change the synapse configuration namespace to a more meaning full namespace;
Provided that the migration tool will be there this change should be OK with the 2.0 release.
Technical Lead & Product Manager; WSO2 ESB; http://wso2.org/esb
WSO2 Inc.; http://wso2.org
email: email@example.com; cell: +94 77 341 3097