The dome will "work" with DTV. Period.
Now, the devil is in the details. The dome will only be able to receive the signal from the DTV satellite at 101. That means that you will not be able to receive ANY DTV programming in high deg. You will need to get an DTV HD receiver but you will won't get any HD. There are also rumors that DTV will be ending there SD programming in the future. If this happens you dome will either receive no programming or limited programming but it would suddenly be in HD (on the assumption that they don't kill the 101 and shift some of their other programming to that satellite). What you certainly will not get if that happens is ANY local Networks and even today using the SD broadcast, not all of DTV's markets are available from 101.
Personally, I would keep select DISH or DirecTV and install the Winegard Trav'ler as a replacement for the dome. You would then be able to get the exact same service that any home user gets every time you park your RV. No, no in-motion but you could watch recorded programming on the road if that's a big deal for you.