Ability to control the end date for Epics in Scrum

In using WF for our Agile teams and applying the Scrum format, we create Epics by entering a Task on the "project" side of the Agile Team which reflects the parent/child relationship of User Stories and Epics in the Backlog. However, the end date of the Epic is controlled solely by the latest Target Date of all the User Stories under that Epic. We would like be able to control the end date of Epics (or just have no end date at all) but by default, they will show an end date of the User Stories under them. Creating a "shell" User Story works to control this end date however those User Stories will show as aging in our reporting. Is there anything on the WF roadmap to have Epics behave/appear similar to other tools?