Bope there is no Dish DVR that can record Off Air Analog and no plans for it eaither. Since most areas now have Digital Broadcasts and analog signals about to go bye bye, there is no reason really to make such a beast.
There really is no need for such an animal from Dish's point of view. 80%+ or so of the US now has LIL which can be recorded, and Dish will probably close this to 90%+ soon. Get your LIL via DBS and Dish makes more $$... good incentive for them to not worry about OTA recording.