hmmm, so you need more than two (or more) random people bonking. Actually, ever seen Zack and Miri make a porno? They sort of hinted at the right idea in there. i.e. delivering the fantasy of a situation occurring at work or somewhere that the viewer could imagine it happening to them.
I guess there's some other TV shows that are hitting the mark, such as Nip & Tuck or Californication where the people and storyline are highly focused on sex but there's still a storyline there.
Again, it goes back to the problem where generally you can't actually do much storytelling or progress in the sex scene it's self. Basic instinct is one of the few examples of a movie where there was story progress for the viewer beyond the blatant fact that they bonked. In that sense, there would be little gained by shows such as californication by having full frontal sex scenes.
Heck, maybe we're just too accustomed to the porn industry where a standard sex scene takes a minimum of 5 minutes and usually 15 minutes. Maybe they could do a good job of it in the mainstream industry with only 2 minute scenes. *shrug*