I often had difficulties explaining to customers how the integration magic used to work and how it has changed.  Most didn’t care as long as their stuff kept working.  I have heard from government customers they use SOAP because it is more secure than REST.  Really?  Duncan has written this article which is an excellent introduction to the two protocols and should be given to anyone who asks “What is ….”.  I’ve been RESTing for awhile now, and I don’t plan on getting clean with SOAP anytime soon.