If Guerrero upsets Floyd, he should be crowned the upset king of the decade. I can see Canelo vs Guerrero if this actually happens, and to me it would be completely justifiable because if Canelo beats Trout, there would be no big fight out there unless Cotto wins a fight against a top 10 fighter and that would set up Canelo-Cotto. But Guerrero vs Canelo would be the biggest money fight to make if Guerrero can actually pull off the upset. Other than that, Guerrero vs Marquez/Pacquiao would be pretty big too, but Arum gets in the way of that.
With that said, I doubt an upset happens, but anything is possible now with an aging, near 40 year old, slowed down great.