You also want to see Mayweather - JMM II. Basically, you'll see mayweather vs. anyone because that's all you know.....moron....
Rios is not an elite fighter. He's good and damned exciting, but he isn't likely to beat elite level opponents, nevermind one of the 'best of the era' kind of guys like Mayweather. He may lose, but he should be put in in with Matthysse, Garcia, even Maidana at either 140 or 147. Those are the guys he needs to be facing.
I personally think Rios carried his punching power very well up to 140, Matthyse doesn't belong in there with him. Matthyse would be TKO'd. Many don't believe it but Rios can and would give him a beating of a lifetime Sure Matthyse is a better puncher but he hasn't been in there with someone as speedy/powerful as Rios Rios also has a granite chin, great heart. He's hard to beat man.