Apache Camel provided the sort of configurable architecture which allows web service messages to be determined dynamically during run time for web services that are hosted in Java environment.
I was wondering whether there is a similar/equivalent framework for applications written in c# and hosted in .Net/SharePoint environment?
A bit late to this party, but might be of use to some people...
This wiki page has a list of alternatives - or it lists Camel as one of the options - https://en.wikipedia.org/wiki/Comparison_of_business_integration_software
Which leads me to suggest BizTalk - but that may be over the top for your requirements.