The author's name is David Walsh--he's a respected UK sports journalist. I read the book when it came out, and found myself depressed at the end--the sport I dearly love is clearly in a state of profound crisis. There were no new bombshells, but it serves a useful purpose in collecting the raft of circumstantial and testified evidence regarding the culture of doping in professional cycling, and the American involvement in that culture since the early 1990's.
While you can pick at individual bits of evidence here and there, the cumulative picture Walsh presents is overwhelming and damning. Of course, the Lance Strongarm acolytes will never be convinced that his seven wins were anything but immaculate. Religious beliefs resist falsification.