Unfortunately the EF does not support promoting parts of an XML column up as direct properties of an entity. You can have an XML column as a property, but the property is treated as a string rather than having the EF map into the XML. Building deeper integration with XML is something we've talked about for a future release but don't yet have a firm plan of when it will arrive.
One thing you could consider doing is creating a view on your database which uses functions in the DB to expose parts of the XML as columns in the view and then use stored procedures to handle inserts, updates and deletes. The EF could then be mapped to the view and the stored procedures.
- Danny