I think we can agree that most people that download TV episodes via bittorrent either don't subscribe to the network that carries a particular show, or don't have the time to watch the show during its regularily scheduled time (and don't have a Tivo). I think most of them wouldn't mind having ads in the downloaded file if it means the download is completely legal. A legal and supported download format/program would lead to far more downloaders, and as a result, faster download speeds.
I've come up with a solution that would benefit these types of individuals, the networks, and companies with products like Tivo. I call it "ad insertion at download". It's a pretty simple idea, and I doubt it would be difficult to implement.
Basically, a consumer would download the "official" client, which would only require them to enter their zipcode. This program could also be built into DVR units that would connect to a broadband connection and do the same thing (with a nicer interface and ability to display on a normal TV). You select the shows/episodes you'd like (same as Tivo), then the bittorrent download begins. The only difference is that this new client will insert ads at predetermined points within a file (designated by the TV networks). The ads included would be determined by the zipcode of the client, allowing national advertising and local advertising. Additionally, ad agencies and networks would be able to charge their advertising clients by the exact number of views rather than estimated ratings (or they could do it exactly as they do now).
This type of system would give everyone what they want: people get a relatively fast download of the shows they actually want to see, networks continue to receive their advertising proceeds, and advertisers deliver content to the people most likely to use it.
Networks get the added benefit of getting advertising money for PAST episodes as well. Say I want S04 E05 of The Simpsons. I download it at a decent speed (the networks could easily provide cheap seeders for every episode they've ever aired) and get either the advertising that was included when the show first aired or updated advertising that someone paid the network a good deal of money for.
Companies like Tivo benefit even more because they provide an easy interface for people to view the shows on their TV rather than their computer. Tivo can charge extra for this if they want, but I doubt they would. It would be pretty simple for them to build into their interface as well.
Sure, there would be people that would mess with the downloaded files and remove the ads, but I don't see this as being any different than a VCR or Tivo. Plus, most people wouldn't bother with the illegal version of the file with ads removed since the download speeds would likely be slower than the legal version. There would also be hacked clients on the network, which would download the file immediately without any ad insertion, but simple authorization would make this more difficult for the hackers. Also, how many people would download a hacked/cracked version if a legal one is available at no cost.
The way I see it, this is an easy way for the TV networks to embrace the bittorrent technology in a way that the music and movie industries haven't. It's easy and beneficial for everyone involved, but more importantly it just makes sense.