At the NextGenUG Fest I gave a talk on Dynamic Data and had a couple of good questions to follow up on. The first was how to sit Dynamic Data on top of existing data layers rather than using LINQ-SQL or EF; the answer is to create a DataModelProvider and associated TableProvider and ColumnProvider to expose the metadata that Dynamic Data requires. There are some samples on the Dynamic Data Samples Site
The second questions was how to hook authorization into Dynamic Data, so that columns/actions only become available depending upon the users’ roles. There is a good set of notes and samples at http://csharpbits.notaclue.net/2008/06/dynamicdata-project-file-update.html.