I think it's interesting that people are claiming it's a joke. Yes, with many MMA fighters it could be a joke. If any fighter tries to play boxing with Mayweather, they will probably lose. I don't think Conor is going to do that. See my comments above for more of what I think will happen.
From what I hear, much of the talk about it being a joke, or bad for boxing, etc. is coming from other promotions, and DeLaHoya, whom Dana said tried to set up Conor to fight against his boxers.
Who knows. We really wont know til it happens. Can Conor compete? Or can he shock the world by fighting with a style that throws Mayweather off?