Wow, everybody just loves this book! I liked it too, mind, but the ideas behind it weren't terribly new to me (I have been discussing the "revolution" phenomenon with other television fans for years, if not in so many words). Sepinwall's greatest contribution to the debate were the interviews, as that was something only he himself could do, but that just made it a good book, not a four-star-good one. Also, there were what I couldn't help but see as three major flaws.
1. First, a mention--somewhere, at least, even if it was just in the section of the book where he talks about pre-"revolution" shows that weren't quite revolutionary enough--of the show "Babylon 5." No matter what you think of that show's quality (and parts of it were godawful), it was in fact the very first novel for American television, and it was on the air in the mid-nineties, well before the true "revolution." It may not have exactly influenced the revolutionary shows that came later, since hardly anyone paid attention to it at the time, but it really did do all of those revolutionary things well before any of the shows Sepinwall identified. Not only was the entire show planned out in advance with big sweeping story arcs, but the Babylon 5 folks even did the fan contact thing first, since rec.arts.tv.babylon5.moderated was around well before the Lost fan boards (and had exactly the same sort of participation from the show's creator as Lost and Battlestar Galactica did later).
2. There was no acknowledgement whatsoever that "television" does not always and forever, amen, equal "U.S. television." What was "revolutionary" for U.S. television was simply par for the course for a lot of UK-made shows, for example, and this is the case for other smaller non-English-language markets too. Two cases in point: the first show of the pre-revolutionary paradigm that I'm personally aware of was Maria Goos's show "Pleidooi" (which aired in the Netherlands in the early nineties) and the first show of the truly revolutionary paradigm that I'm personally aware of was her "Oud geld" (which aired a bit later in the same decade). Not even acknowledging the existence of different television traditions in other countries isn't just arrogantly, gallingly U.S.-centric, but it was also a missed bet, because a discussion of that could have explained/explored what it is about the American television market that kept the revolution from happening for so long in the U.S. by comparison (funding? the way the industry is set up? I don't know, but I wish Sepinwall had told me!).
3. Finally, this one is less egregious than the other two, but it's still worth a mention: it would have been nice if Sepinwall had mentioned the fact that there are other American show formats that pre-dated "the revolution," but which also told continuing stories. One is the miniseries, and another is the soap opera. Now, I am totally convinced that the dramas of the "revolution" are in fact an entirely different show type from these, but I can tell you that when I bring up the whole "television is so much better now than it used to be" argument among friends who don't pay quite as much attention to these things, and I bring up how the medium is now used to tell bigger stories over a longer period of time, the arguments always come up that: "oh, come on, 'Dallas' did that back in the '80s" or "wait, what about 'Roots'?" Some arguments from Sepinwall about why these are not in fact the same thing would have rounded out the book quite well.
All that said, I really did like the book. It's a good read, it builds a good argument, and it's full of really interesting tidbits you're not going to read anywhere else. It's definitely worth the money you'll pay to buy it, so you should do so if you're thinking about it. The flaws just leave me unconvinced that this is a four-star book, that's all.