Considering they have been testing Smithsonian HD, MojoHD, Tennis Channel HD, and MGM HD for awhile, if they have the contracts signed, all they need to do is make the channels available to subscribers. Someone in a senior position has made the decision not to release anymore national HD, instead concentrate on eastern arc.
The sad fact of the last couple months is, Dish Network has become a third and in some markets fourth tier provider. Directv and cable carry more national HD (excluding voom). Scifi and Usa were prime examples of that, as my local cable co's had those channels way before Dish, something that used to never happen.
Eastern Arc will not help Dish's bandwidth crunch as they will not be able to take down any existing channels from 110/119 until they get all subscribers in EA markets to migrate. In my opinion its going to be a big pain in their ass for at least the next year and a half.