DTV is not going to have that many national HD channels, but I guess if you factor in locals. Besides, do not count on seeing any new national HDs until at least late summer/early fall at the earliest. DTV does not launch Direct TV 10 and 11 until July. Take a few months for testing and they wont have any transponders up until at least Fall.
Someone over at the Satellite Guys forum actually called the head of PR at the SCI-FI channel (one of the HD channels listed in the D* keynote today). She said there is no SCI-FI HD channel. Me thinks D* is fibbing.