WCBS-DT is an OTA channel for me, and East and West feeds of HBO-HD and Showtime-HD have been available for a couple of years on C-band. The Dish Net demo channel is a 7-minute loop and unimportant, plus it's available in the clear with the Unity Motion receiver. And one HD PPV movie per week is hardly an incentive.
The only compelling reason for me to have Dish Net is the recording capability. If they remove that I have no reason to maintain yet another duplicate set of subscriptions to HBO and Showtime with Echostar.
If a PVR comes along so that their content continues to be recordable, then that's another story. But even then, unless it allows archiving of movies to tape, it might not be worth it to me. A few hours of HD timeshifting capability is not going to be enough.
That said, the providers' HD offerings and hardware are changing all the time, and every change prompts a re-evaluation. But if my 5000+modulator ceased working today, I'd have no reason to remain a Dish subscriber (today).