You can couple OTA with a 3 LNB dish. However, if you want HD, you WILL have to upgrade to the new 5 LNB dish which carries Ka and Ku frequencies which you can NOT couple with an OTA signal. Keep in mind all HD in the near future will be off MPEG2 and more than likely not on the current 3 LNB satellites.
If the only HD I'm interested in right now is OTA ... and I keep the 3 LNB Dish, will this work? (watching an OTA program and recording another OTA program?)
Of course, if I knew that I could get an installer that I could communicate with and seemed to be 100% adept at what he was doing ... I might not mind his making holes in my roof and upgrading the dish.