If they are going to have a wild card team then there should be 2. The way it has been. it makes no difference for Boston and New York who wins the division and who is the wild card. They are both treated the same in the post season, thus there was no incentive to compete for the div title. Now that the 2 wild card teams will have to meet for a 1 game playoff, teams will be competing tooth and nail to avoid that.
OTOH, the season is already far, far too long and 4 teams a league work well IMO, without unecessarily extending the season, yet again