Other than INHD & INHD2 (not gonna happen) and my RSN in HD, the other HD channels are of no significants to me. More HD channels are always nice, but I would rather see E* focus on improving quality over the next three months: resolve encoder issues, solve bandwidth issues, solve VOOM-Lite, fix a growing number of bugs in their ViP receivers.
If I had to guess, I think E* will add three additional HD channels to the DishHD lineup later this summer: FoodHD, CinemaxHD, and perhaps MHD (if they price is right) or WealthTV, and several RSN HD channels on spotbeam.