Caron is a potential 20 PPG scorer and 2-time All-Star who is more than capable of returning to that level, despite his injury riddled past.
Butler could easily become the starting SF of this team, if Danilo is not ready to hold down the starting spot, Caron could also mentor Gallinari and give him good advice on how to get his points in the NBA. If Danilo is kept as the starter, Caron would instantly become one of the top 3 sixth-men in the League. With JR and Wilson Chandler most likely leaving, we will need a scorer off the bench who can score in bunches and hit big 3's and basically score at will.
Also, if Butler comes to Denver will have one of the greatest characters and locker room guys in the league. (Who could be a better teammate than a recovering Mountain Dew addict and an infamous on court "Straw-Chewer") Butler is already one of my favourite players in the NBA and it would be great for him to be on my favorite team.