I think this will be one hell of a fight. Mauricio Shogun Rua is claiming all his injuries are healed, and he was impressive in his last fight against an admittedly aged Liddell.
Lyoto The Dragon Machida, on the other hand, is one of the most elusive and best defensive fighter today, and has shown he is in top form against even the quickest of opponents [Rashad Sugar Evans].
Personally, I see Lyoto taking this one, merely because Shogun is a bit slower. He'll hae to find some way to corner Lyoto Machida in the octagun before unleashing a fury, and that's been proven to be no easy feat.