Last time I checked, HD went from being:
1) a $20 addon to
2) a $10 base addon and a $10 platinum addon to now
3) just a $10 addon.
I'd say that, thus far, competition has been very good for the HD consumer. I emphasize the creation of the Turbo or Absolute packages because of the dissatisfaction with the lack of additional HD programming being added to the packages. But I would also attribute the existence of those packages to competition over HD customers.