All right, to clarify, probably a dumb question: If I upgrade to HD now and keep my address (17837), I will not get HD locals (Wilkes-Barre/Scranton). If they give me a new HD dish as part of the upgrade, will I still get SD locals, or lose them altogether? I thought my current dish has some kind of dual capability because the locals came from a different satellite than the other stations....
Your SD locals are currently on 110 or 119, I forget which -- but you're currently receiving both satellites anyway. If you were set up a long time ago, you'll have an extra-large dish that also receives 105, because the locals were originally there. Now, nothing is there, so the dish is just extra weight and power drain, and hornets like to live in the LNB cowling.
To get HD, they'll need to add a completely separate dish pointed at 61.5. I have no idea if they'll swap out your Superdish, if indeed you have one, for a Dish 500 for 110 and 119, because I'm not familiar with all the different types of switches they use. But you WILL need two dishes. You won't be able to get an Eastern Arc dish (61.5, 72.7, 77), and hopefully the installer will know this and not try to give you one, because the SD locals on 61.5 are on the same spotbeam as the HD ones, which doesn't work in your area.
So, to make a long story short, you can get HD and still keep your SD locals, as long as the installer is familiar with our area.