I won't believe his retirement until it actually happens, and then lasts for +2 years. I've fallen for his retirement announcements 3 or 4 times. How many is it now?
But yeah, I don't think he deserves Shogun or Machida, with tapping out Toney or not. To me it kinda sounds like he might be using his retirement to make a quick path to the top of the LHW division. "Hey, give me Shogun or Machida or I will retire."
I just think his best days are behind him, and I wouldn't be really excited to see him fight one of those two. He would probably retire with a loss anyway. His perfect retirement match would have been against Big Nog, but the UFC jumped the gun with that one.
If he's serious about retirement, I think he should fight Cro Cop. If Cro Cop wins, Couture retires. If Couture wins, both retire.