I noticed a 'discussion' on the subject on the Smizk's vaunted PG.  Were baseball to decide to move the game I doubt it would be a decision of principle. The players association has come out in public opposition of the law, and  I would posit that there's a distinct possibility that a number of Hispanic players and coaches may boycott the game, which would be an absolute disaster for MLB, and as a huge corporation I imagine this is something they'd prefer to avoid.