I think this is an interesting match up and is probably what both of these guys need. Hughes needs this fight to tell him if he can still hang, and Diego needs this because it will tell him if he is really evolving. I can't decide who I think will win, but I will be rooting for Hughes. I think this fight is still winnable by either of these men.
I don't think Hughes needs this fight to tell him if he can still hang, he shouldn't anyway. He knows he has no chance of beating anyone in the upper levels of the WW div anymore like GSP, Fitch, Kos, Penn. He can beat pseudo cans like Serra and Renzo Gracie. Guys in the upper middle class of the WW div like Sanchez or Kampmann he loses to most of the time, but has a small chance of beating if they get careless. Pretty easy win for Sanchez I think, Hughes is just too old and too old school.