Not only is BizTalk sort of “Contract First” out of the box, there is now a tool for BizTalk to actually give you the same experience the thinktecture WSCF tool gives you(http://www.thinktecture.com/Resources/Software/WSContractFirst/default.html).
The new tool is written by Molnar Tibor and is called BiztalkWscfClient: http://geekswithblogs.net/mtex/. It currently supports BizTalk 2004 and VS.NET 2004, but he is working to upgrade it for BizTalk 2006 and VS.NET 2005 very soon.
This is very cool! I can't wait to get the latest version.