The idea of the Yankees attempting to void Alex Rodriguez's contract pops up every now and then even when A-Rod isn't in the middle of a major ongoing story involving continued use of banned substances, so I certainly can't say that I'm surprised it's become all the rage with columnists both national and local since the Miami New Times story came out yesterday. Still, there's no more chance that the Yankees can actually do it today than there was last week.
The first, and biggest, problem for the Yankees to clear is that A-Rod's contract is guaranteed, and iron-clad under the rules of the CBA. The Yankees can not simply decide, unilaterally, to abrogate the contract, nor can they go before a judge or an arbitrator making ad hoc arguments as though the law had to be made on the fly due to unclear rules or something. Disciplinary reasonings won't help either, since the CBA also spells out in detail the exact punishments for A-Rod's alleged offense, and they don't include the voiding of a free agent contract. If the league decides to take action, Alex will be suspended for 50 games as stipulated by the rules, and that's that. Indeed, the fact that the punishment is explicitly prescribed by the CBA more or less shuts this whole discussion down, as there's no way the Yankees can expect to find a judge who would find that they are somehow special and can operate outside the parameters of the CBA, which is exactly what they'd be doing.