Among many of the new features you'll find updated EDI Tools, XML Schema Aware XSLT 2.0, and XML Schema Aware XQuery 1.0 processing.
You can also check out a nice DataDirect XQuery video tutorial that shows you how easily you can quicky build complex and powerful XQuery expressions that access relational databases. Last, and certainly not least: Stylus Studio 2006 now allows you to deploy XML Deployment Adaptors built with Stylus as runtime components. For developers facing integration challenges, this is a powerful and flexible mechanism to get hetereogous data to work together.
More details, including licensing details are available here.