Capacity is not the issue now but may be the issue later (particularly for HD locals). I think that Dish Network will try to take a different approach in that they will try to launch more national HD channels than HD locals because there will be more demand for national HD channels since it would net the customers more channels in HD vs. saving space for additional HD local markets.
I wonder what the next plans will be once they get all the HD locals and national HD channels up. Probably a higher resolution HD or shows becoming VOD.