A Cotto fight would have been huge as he was undefeated and had beaten Mosley...however, Bob Arum was clearly in the way so we know why it didn't happen. Would have been a huge exciting event though most definitely, especially with both being less experienced than when they actually fought and Floyd seemingly less adapted to 147 body wise. We would probably have seen a more mobile looking Floyd the way he was against Hatton early.
Mosley in '10 was equal to that Cotto fight would have been IMO, because Mosley had absolutely destroyed an uncrackable Margarito who was a massive favourite. Mosley showed a new lease of life and actually destroyed an opponent then confronted Floyd TO HIS FACE in this ring the buzz was off the charts! Floyd just doused those flames too well when he dominated so well - making haters flip flop saying it was a pointless match up.