I think the standard model of television watching will will be gone before they ever allow full on nudity in regular network broadcast shows.
We are already moving away from the standard prime time viewing schedule with so many PVR's and TVO in use and the time shifting of programs. Then when the US finally goes all digital you will (hopefully) see a large shift to everyone getting their shows through cable & satellite providers. Once that happens, you can get your shows as pay-per-view, subscribtion, and downloads. We already have it here in Canada where you can watch an episode of your favorite show at anytime just by selecting it from the "watch on demand" menu of your cable provider.
In time, I believe that regular "network" broadcasts will have the usual stuff like news and reruns, American Idol, lifestyle shows, entertainment news, and other "safe" shows fillingup most of their timeslots. All of the television series will be "view on demand" that you can chose to watch at anytime of the day or night. Once that happens, and people have to activily "download" a show to watch then the restrictions on nudity and swearing and violence will start to go away, because "Timmy" can't accidently turn on the TV and see it, you have to actually choose to see and select the show (with warnings I am sure) to watch it. That level of control will allow the networks to "get away" with more.
As, an aside, I also think you will start seeing these network shows that you have to "select" to watch being shown, highly edited, for free on the regular broadcast by the networks. These would act as "ads" for the downloadable, unedited, shows and still give added revenue from the advertising that they generate.
How would this work $$-wise? well, each show you "watch on demand" would cost you .99 cents, and I'd bet you could get series packages you pay for up front and then get all the episodes of that series for free, etc...
It will work out.
