No it's not. Pete bitched and moaned about this yesterday in the chatbox. The A's and Rays both draw shit for attendance and play in the worst stadiums in MLB. Here's a nice article, I suggest everyone reads on the topic:
http://www.athleticsnation.com/2010/12/29/1897208/contraction
Contraction would lead to several positives for MLB.
*Improved quality of play. With 50 less major league players, the league would eliminate players like Yuniesky Betancourt, and other below replacement players who don't belong on a major league roster.
*Increased revenue sharing for the remaining 28 teams. The Rays and A's both draw shit for attendance, so they both require a lot of revenue sharing to stay a float. About thirty million a year each. If the two teams were eliminated then that sixty million could be split by the remaining teams.