I think the future is not in streaming downloads, but in properly managed download services that have interactive functionality with TVs and A/V receivers.
Downloads that you put in your queue, as you do with BB Online, but then are downloaded to your PC. Maybe 3 or 5 movies are downloaded, and you return them when you are done with a mouse click, or an option on your TV screen. The movies can be HD or SD, but can be chosen by users for what their display supports.
If you pay for unlimited rentals, 3 out at a time, every month, then you will have 3 available to you at all times. It may be 12 or 24 hours for a rental to download to your PC, or whatever is storing the movies (receiver? TV?) but then it will be available until you return it. Stop with the stupid 24 horus from first watch to 'delete' of movies! Let me decide when I'm done viewing it.
Things that are really cool is that new movie releases could download to your video servier a week before they are 'officially' released, then on the date of release - at midnight, the movie beomes avaialble for playback.
No sold out titles, no waiting days for a movie to arrive, no scratched discs. It also adds the capability that even those with slower internet connections can take part. It may take longer for them to get the downloads, but when they get them, the full movie will be available to them - not streamed with the headaches that accompany streaming.
I could totally see that as the future - and it's several years away at least.
