Yeah, he's serious. I thought Hughes wouldn't want to continue his career after beating Serra because he's just going to linger in the middle of the pack forever. Seems he feels the same way: Good luck, fuckhead.
No matter the outcome of their fight at UFC 100, I'm sure the UFC will want to see Hughes/Alves II and not Hughes/St. Pierre IV. Even still, if Alves wins the title, Hughes isn't the top contender. It will likely be Fitch, who has beaten Alves already. There is no point in having Hughes fight GSP again. GSP likes him and would like to fight him again, but it is pointless. GSP annihilated Hughes in their last two fights. Hughes/Alves II isn't even very interesting. Hughes took Alves down but didn't do any damage in their first fight. Then he got wrecked. But if Hughes only wants to fight one of those guys, not much else Joe Silva can do.
Why does Matt Hughes want to go out on a lost? The guy should just take his victory over Serra and retire.
It was a terrible win; I'm sure it was unsatisfying. He's looking to go out with a bang. He will--but it will be the sound of his jaw breaking.