That fight will never happen, Coleman was originally brought back to the UFC to be a punching bag for Lesnar. With that fight not happening option two was a rematch with Shogun (whom just like Wandy wont adjust/or will be a success in the UFC because of the cage and the rules being different than in Pride ex. no stopping or flying/soccer kicks while your oponent is down, not to mention the level of competition is higher here) who will beat him Coleman but not without taking some punishment on the way. I have respect for Coleman, after all he is the godfather of ground and pound but with younger more rounded fighters it will be tough for him to be a contender. Wandy needs to change his boxing a tad, stop swinging wild and open as he did with Rampage, and maybe he could be a contender and posibly a champ again. THe idea of a drop to 185 does not make sense.
The only way I see Coleman vs Wandy is if by some miracle Coleman breaks a bone on Shogun again, as far as Wandy & Coleman go, they had squashed the beef a while back so the fight makes no sense unless you really dislike Coleman and want to see him getting destroyed by Wandy.