I'm not going to invest any hope in Cable/Sat "downloadable" HD content. All of the current "on demand" SD material from T-WCable is pay-per-view, and MAR to 1.33:1. I'm sure when HD gets around it'll MAR to 1.78:1. Plus I'd like to buy a movie once, not have to pay $9.95 every time I want to watch it.
Even if it magically becomes "pay once for unlimited viewings" and OAR, the cable company will never have every movie available to watch at any time. (How many millions of terrabytes would that add-up to?).
Right now its looking like SACD & DVD-A part deux. Which is fine with me really, I'd rather a throwback to LD days: Premium video & audio, none of the throwaway bonus crap, and no more fullscreen pan&scan.