Undefeatable commercial elimination
I've written elsewhere about the doom of the TV commercial, and as you may know, we represented Replay TV owners in their fight to not be declared lawbreakers for skipping commercials..
Commercial skipping tools have existed for some time, my old VCR has a complex automatic commercial advance. DVR makers have been scared against doing it for a while it seems.
However, an algorithm exists that makes it a fight they can't win. While networks can try to fool automated commercial skipping algorithms, they can't fool large numbers of live people.
One could build a commercial skip (or general "boring parts skipper") in PVRs by having the first party to watch a show be required to manually fast forward over the boring parts. As more and more people do this, patterns will emerge. Combined with automated algorithms looking for the usual (fades to black, standard time periods, changes in sound patterns) it would be possible to get a very accurate measure of where the commercials and other boring parts in a show are. So accurate you could even delete them from disk, though there isn't a great need to do that.
Of course, you would need to use only people without a reputation for dishonesty. If one person's skippings don't match the others, or they do this a lot, don't use them. You could also do collaborative filtering techniques, to see people who skip what you do, or who even pause to watch certain ads (like movie trailers) as you do.
This could apply to not just shows with commercials, but other shows with boring parts. Pauses in sporting events. Boring speeches in award shows and political press conferences. Sharing your skipping with people of similar tastes could cause on-the-fly personal edits of shows ready within an hour or two of airing.
Sometimes you would want to watch first and you become the editor. Most of the time you would just be the beneficiary. If you don't like the editing one group of people are doing, you could switch to another.