Generating code from UML can be very useful, although the usefulness of the result depends on what type of UML diagrams you use.
We’ve been part of several large projects where we used UML class diagrams to model the domain model, according to the DDD principles. Domain models (being OO persistable class models or Web service model) focus on structural patterns, i.e. how the different constructs (like entities, values objects, aggregate, etc.) relate to each other. For structural models we prefer UML class diagrams as we feel the convey information in a much better way than pure textual DSLs.
Visualization of relationships provides a better overview and is a good platform for communication.[/infopane]