You know what this reminds me of? People are only now understanding defense. This explains why Abreu didn't get any offers close to what he was expecting, and Dunn. How do you quantify catchers? Soon, I hope, someone much smarter than anyone here will come up with something and then you'll notice that Posada is the Abreu of catchers, and Molina is the Ozzie Smith of catchers.
Look, I like Posada. The Yankees are a better team with him. However, what he gives offensively is given back defensively. Same with Molina. I think the Yankees win more games with Molina than with Posada. However, they win more with Posada than any other backup catcher they may have.
As for the pitchers, Wang was 9-2 and Mussina was amazing. Now, I think for pitchers who live on the corners, like Mussina, Molina is irreplaceable. Pitchers like AJ or CC or Joba will not be as affected as pitchers such as Pettitte or Moose.
Anyways, back to the subject....the Nady injury won't hurt that much. Swisher is the better player overall, and you'll have a rotation of Swisher, Damon, and Melky for two spots, and this will allow Posada to DH more.