As announced in today's Feedback Friday, the Tabula Rasa team has been working on a way to present low-level instances in what could be considered a "hard mode" of sorts. The first of these is the Caves of Donn instance which now has an Epic version, accessible through the CELLAR Arena.
This Epic Caves of Donn instance has Epic versions of the Caretakers, Technicians, Soldiers and the brand new Ravagers and Seekers created for the Back-to-Earth campaign. This instance is repeatable, allowing players to eventually gain all rewards in addition to the XP, Prestige and Mimeomech. Admittedly, the developers report that the instance doesn't have as much polish as they'd like.