Yes you are correct, this feature did not make it for the latest release, for which we apologize. Actually the feature is part of a major project we are working on which consists of re-factoring the complete Visual DSL designer. We hope to be able to release the much more stable and improved version by Q1 2011 where the mentioned feature should be available.
Again, we are sorry for any inconveniences this might have caused you.
the Telerik team