What makes good television?

There's a show coming out on MTV called Skins (trailer below). It's been running for 3 or 4 years now in England so, obviously, the US has to try to improve upon it. From what I can tell, the show is about teenagers. And it's supposed to be edgy, gritty, real - drawing upon real, live teenagers for inspiration.

The New Yorker has a short piece about it here and Paste Magazine lists it as one of their ten TV premieres they're looking forward to this month.

My question is: what constitutes quality television? The moral effect shows like this have on the viewer aside, is being "true to life" enough to make a show "good"? The assumption seems to be that as long as it stems from true-life stories of teenage craziness, it should be good... or at least interesting. Or perhaps it is the moral boundaries that it will be pushing that's garnering the attention.