Two comments.
Bobby Abreu. This Phillies team is going to win somewhere between 83-86 games. The last five season they won 86, 81, 86, 86 and 88 respectively. The fans got sick of that kind of consistancy and demanded the owners fire Ed Wade. They did, Pat Gillick took over, overhauled the team, and apparently made a tremendous amount of progress. Last year they were two out of the wild card with three to play, and this year they are two out of the wild card with three to play.
Every year some players step up and some falter. The Phillies had enough players step up to account for the absence of Abreu. One player is almost never the difference in a championship club. Ryan Howard has hit 30 home runs and gotten on base over HALF of the time since the All-Star break. Was he moping in the clubhouse the first half because Abreu wasn't hustling? I doubt it. The truth is this team went through hot stretches when Abreu was still on the team, and had bad stretches when he wasn't.
Second, home field advantage. Historically the home team in baseball wins about 52% of the time. It's generally not a significant factor except for extreme ballpark anomalies, such as Coors Field.