The networks are in a world of hurt. They've managed to survive in a world of cable and satellite broadcasting and rental tape and dvd competition because free television is free, and free tends to have some staying power. Add to this their exclusive first-run content (sporting events, the hit shows like Lost, Desperate Housewives, etc.) and you see a set of battleship-sized companies trying very hard to compete in a destroyer world. Or something like that.
So along comes TiVo, which devalues not only the networks' commercial advertisement platform, but now you can have people watching multiple shows simultaneously! The timeslot war was the key to survival back in the day, but TiVo and similar products take the damage the VCR did to that model and ups the damage significantly.
The response of the networks is to play a little bit with the minute-by-minute timing of their shows. The RIAA is behind all sorts of DRM attempts to make CDs un-rippable and whatnot, and the MPAA has its regional encodings and other DRM stuff for movies, and while the networks will eventually attempt to disable recording of broadcast media in some way in the near future, this current attempt is merely an inconvenience that does something essential.
That is, it makes people take notice. The TiVo and even the VCR communities are noting that their simple grid structure is being messed with, and they don't like it. Even my own father, who could care less about some of the other rights that are being tested in the consumer space (DRM, software licensing, privacy concerns, etc) has already become aggravated by this little slip in the timing of his shows. Those loftier issues that don't bother him [yet] are still out there, but that first little pin prick caused by this little gesture by the broadcast networks is piquing his attention.
I only hope that the tv-watching community in general starts to take notice of these things. Those of us with a TiVo can grab another one, go with MythTV or one of the other free variants and tweak schedules accordingly, or maybe someone will form a little show-swapping network (since surely there's nothing like this already) so that cooperative efforts can thwart this early volley. I've said it before and I'll say it again, until the masses are inconvenienced in a meaningful way by the actions of these corporations-- that is, when the problems move from being those of the Linux and MacOS crowds to those of the tv-watching and voting crowds-- our grumblings will continue to be viewed as such.
I'll miss a minute or two of Lost for the cause of tv freedom any day.