Burnett, in Game 2, actually looked better than Sabathia in Game 1. While CC is inarguably the superior pitcher, the superior pitcher isn't always the star that shines the brightest in the postseason (see Denny McLain and Mickey Lolich from the 1968 Tigers).
Despite the fact that Manuel has given himself a better chance to grab a second series victory in Game 5, he has put his team at a definitive disadvantage in Games 4 and 7, and an easily arguable disadvantage in Game 6 in which Pettitte appears again. While Andy is the least reliable out of the "Big 3" on the Yankees' staff, he is a seasoned big game pitcher with a wealth of World Series experience and success who has been very hot lately (including in his Game 3 win over the Phils on Saturday). And Cole Hamels and Pedro Martinez (or possibly J.A. Happ) have not been, to put it miidly (especially after Cole's own Game 3 start).
The Phillies needed Lee to pitch three games in this series and especially Game 7 it even gets to that point. The rest of their pitching staff just can't matchup with the Yankees' rotation and bullpen. Throw in the slight offensive advantage for New York and the facts seem to point towards an eventual victory for the New York in the series, up 2-1 going into Sunday's game 4..
Manuel is an underrated manager, but that old school mentality of letting a guy "finish what he started" might be the key decision that will give the Yankees the advantage (matchup-wise) that will push them past perhaps the best opposing team they have faced in a World Series since the mid-1960s battles against Koufax's Dodgers and Gibson's Cardinals.
Both of those series where the Yankees, inversely, were the ones whose offensive prowess failed to compensate for the inferiority of their rotation in a matchup to matchup sense, game by game, in the series. Ralph Terry was a very good Yankees' pitcher but he was sure as hell no Bob Gibson, a guy who regularly pitched three games in the World Series, winning the MVP in the Cardinals victory in 1967. Cliff Lee apparently isn't cut from that same mold.