Well he's already talking about a ODLH rematch in a recent interview which worries me.
I think if he loses, he'll probably go the rematch route if it's on the table. Although it'll be very tempting for Oscar to retire after a defeat over Mayweather.
Sad to say that I think Floyd will plunge into a major catasrophic decline if he loses. Almost a Naz-esque plunge.
If he doesn't get the rematch with Oscar I think he'll go on to win a couple unspirited matches with little fanfare.
He's one of those guys that, mostly through his own attitude and actions, has built up this invincible persona. And whenever these types of guys loses (like Naz or Tyson) it affects them a lot more than a fighter who's faced adversity earlier on in their career.
This fight is do or die for Floyd.