While reading bob meyers blog post on Report builder 2.0 and report models he mentions an immenent (?) update on report builder 2.0:
Rest assured, though, that we are hard at work on closing the gap as soon as possible. We are also working on a number of exciting and valuable enhancements to report models and report model queries that will enable new scenarios while making the query design experience even easier.
Great news for all report model users.