Ok guys this has been beat to death and I'm starting to feel bad for all you who worry so much about it. Unopened bottles are a no brainer. Stick them in a cabinet or whatever and don't sweat it. Hell I've got 15 bottles in the cabinet that holds up my fish tank.
I've had bottles open for what seems like forever that seemed just fine. If they are still open after a year then why even buy it in the first place. Phone some friends and drink up.
And for the worse case situation and one starts to go "off", here is the simple solution. Have your first drink or two from a drink you know to be "fresh" then switch to the other. You won't even notice.