Our Data Dynamics Reports product has sophisticated support for building a report from XML data. For example, since we use XPath expressions to select nodes to bind the fields in the report to, you can bind to data with complex relationships in XML. This walkthrough in our documentation walks you through binding data to XML.
You can download There area screencasts that show more about the product here. We also have this screencast that shows a little bit about working with XML data and how you can let end users create reports from XML data using our end user designer control. This one shows how you can embed the end user designer control into your application and the end user can design a report without knowing or understanding XML at all.
I hope this is helpful, let me know if you have any questions!