Microsoft offers REST support in BizTalk Server 2013 through the WCF-WebHttp Adapter. Something that has been anticipated by BizTalk developers for sometime. With BizTalk Server 2010 there was already quite a demand resulting:

in a TechNet Wiki Article called Invoke ReSTful Web Services with BizTalk Server 2010 describing a solution to consume Restful services with BizTalk 2010,
and a REST