Major Description
There is a small leakage of informations between XML definition and the generated Object.
For example if you define a column as required="true" it would be good to get this information in the object. So there could be a method like isMandatory(COLUMNNAME). One application for this could be generic analyzing of objects before saving to avoid SQL exceptions.
Other informations would be size, scale and description for example.
Of course we could retrieve this informations from the database but this means that we have to communicate with the database and there could be database specific inconsistency.