As for broadcasting the popular downloads later, it won't fly with advertisers. The downloads, if any, will have to be made available after they air.
Not to mention that the number of people that would have the wherewithal to actually use such a system is rather small.
These are factors I've already considered for my own channel. For now, any airtime an advertiser purchases on my channel will also include on-line airtime via live streaming and BitTorrent. I have to generate proper data on the effectiveness of on-line advertising before I can put an accurate price on it.
Even if the CBC did distribute everything on-line, it doesn't mean they know how to do it properly. When the CBC distributed last year's "Canada's Next Great Prime Minister" via BitTorrent, I was not only surprised at the incredibly poor quality of the presentation (interlaced signal, improper aspect ratio control making everyone look squished, bad frame rate), I was also surprised they didn't include any ads whatsoever. For what was a first try by a major network, this was a huge disappointment.
I reprocess the video to correct the mistakes, and added the logos of the show's sponsors at the upper-right corner of the screen to demonstrate the ad bug concept I plan to implement.
The CBC can successfully bridge the budget gap, but they have to do something they haven't done in a very, very long time. They have to innovate!
The CBC radio show "Q"is already doing a great job in this domain by distributing the video recordings of their interviews on YouTube including the infamous Billy-Bob Thorton blow-out. How many hits did that one video get? And how does that compare with the average rating of a Canadian Show?
So many incredible opportunities out there, but the CBC brass simply can't see past their own anus.