I like to do this kind of thing. Humor me if you will.
If they happen today, who wins the rematch?
BJ Penn vs Diego Sanchez- let's make this a 162 lbs catchweight fight
Penn still wins this. Diego tries to overwhelm people with his activity and that is something that just doesn't work against Penn. This is more of a bad style match-up for Diego. His TD, clinch, and striking isn't good to overcome Penn in any single area.
Benson Henderson vs Anthony Pettis
I don't know but it looks like we may get to find out soon.
Dan Henderson vs Anderson Silva- let's make this a 195lbs catchweight
Anderson Silva would win again, even more convincingly. The problem is Hendo has become so dependent on that right hand bomb that he has stopped his other techniques that he used to do to set it up. He was already picked apart in their first fight, the second one would be even worse. And since Silva finally got serious about his TDD he would probably give Hendo decent issues there. I hate to say it but Hendo wouldn't last a round.
Andrei Arlovski vs Roy Nelson
Nelson puts Arlovski to sleep within a round
Carlos Condit vs Rory MacDonald
Both fighters have gotten better. I am a huge Condit fan and picked him to beat GSP, but I think Rory wins this rematch. The only real difference is the speed at which GSP covers distance, Rory uses strength to try and make up for it. Condit would probably win a traditional striking match, but with the threat of TD's he probably won't ever get comfortable. Still I would like to see Rory try to recover like GSP did.
Dan Henderson vs Rampage Jackson
Hendo would win. Jackson beat Hendo the first time by having a better gas tank. While Hendo isn't the energizer bunny, if he put the beating onto Rampage that he did Shogun the fight would be finished. Rampage has lost too much in his step, power, and accuracy.