I am a BizTalk Developer in Plano Texas – and recently earned the Microsoft Certified Technical Specialist credential (MCTS: BizTalk 2006).  Also, a former vice-president of the Dallas area BizTalk User Group (http://biztalkusergroup.org).  Currently working on a longterm contract with a large financial company to implement BizTalk 2006 r2 using ESB (Enterprise Service Bus).  The items I’d worked on involved a lot of FTP and the File Adapter to UNIX using Windows Services For Unix 3.5 (that was special); lotsa maps; lotsa custom pipeline components; orchestrations with direct port bindings; etc.  Next on the plate is to get into the SOAP Adapter, LINQ, WCF, etc.

These things will be moot for the cutting edge enterprises that implement WCF & WS*.  So continual upgrading skillsets.  But that is the way of the BizTalk… every two years a fundamental shift.