I love Gracie, any Gracie. Ryan, Ralph, and Renzo Gracie are my favorites. I live winthin walking distance from the Ceasar Gracie fighting acadamy (where Dave Terrell and Nick Diaz got started)
With that being said, and as much as I love what Royce has done for the sport and UFC in particular, Matt Hughes will dominate.
You have to remember this is in front of the California athletic comission and the Gracie strings can't be pulled. They're well-know for making their own rules (10 minute rounds, untimed rounds, etc.). This can't be done. It's 5, 5-minute rounds (because it's a title fight). It would be even worse if it was just the 3, 5-minute rounds.
Okay, you need to understand that in BJJ, (braz. j-jitsu), it takes time to get things working for you. That's why Royce did so well in the begining (when fights were untimed), it fit his game plan. Pull gaurd or jump gaurd, and work from the bottom while the guy on top tires and slipps up and makes the 1st mistake.
With 5 minute rounds, and UFC in paticular (much different that Pride in japan), The crowd heavily influnces the refs decision to stand them back up. They just want to see people swing for the fences. The crowd (UFC, that is) boo's when the fight goes to the ground, even if both guys are working their asses off. That's why I dislike the UFC in comparison to other venues.
I actually seeing this fight sucking. Matt Hughes will get 5-6 takedowns and not get taken down once. He'll be on top the whole fight. Matt may look like he's in trouble with a triangle or something else, but should slip away. Royce can take an ass beating, that's why I see this a unanimous decision goint to Matt Hughes, easily.
By the way, I actually HATE Matt Hughes as a person (jerk and cocky) and a fighter. I hate ground and pound fighters, they bore the hell out of me. I'm the biggest BJJ fan in the world and know Royce doesn't have a chance, but I'd love to be wrong in this case.