I doubt we will see a big name boxer in his prime enter MMA, the money is very poor, a top name boxer can make much, much more boxing than trying MMA. What is more likely to happen is a big boxing promoter will relise they can get the top MMA fighters to box the top boxers because the MMA guy would make much more money boxing than they do fighting MMA. And it would probably be a huge sell on PPV. It is win/win, the MMA guy finally makes some real money, a top ten boxer would make good money and get an easy bout, the promoter would make a killing. Imagine 'Rampage' boxing a top ten boxer. And Liddell also. They would get killed, but it would draw a huge crowd, boxing fans and MMA fans. I actually wish a top promoter would put it together.
I don't know if this has been posted, go to youtube and type in "al bundy's take on mma" the mma talk starts at about 1:35. I think he makes some awesome points about boxing and mma.