In baseball, I am a traditionalist. I'm opposed to both inter-league play and the wild card.
One justification for the three division setup is that it prolongs the pennant races.
Well, sometimes. But not always. For instance, this year the playoff teams in the American League have been known for a week: Sox, Yankees, Tribe, and Angels. Whether the Sox or Yankees win the AL East isn't really important.
However, consider the case if the American League still had just two divisions. As of today, the Tribe would be in first place, half a game ahead of the Sox, with the Yankees charging hard two games back. It would be a great race.
I recognize that some years the new format is good for creating excitement, but it's worth noting that some years the regular season is cheapened. That's the case this year.