The word is that the Cubs are "paying more than half" of his salary. If the Yankees end up having to pay 10 of the remaining 24 and give up junk, I'd still say that's exactly the kind of move they should be making, given that they want to contend this year.
That being said, they're in a lose-lose situation. Even if they decide to tank it, and get prospects for their best players... their attendance is tanking fast already. Their organization is popular because they're winners... if they have a s*** team, their fans will look for other teams to root for quickly.