OK, I'll give it a go:
(Mundine has been offered the fight in UK with options a way back, if I recall correctly it was a shitty offer mainly because of the options, but if he really wanted Calzaghe he could have taken it)
(Mundine has already had a chance and lost, but he has the right to another shot as mandatory and has been offered the fight, but he declined to fight Nievas stating that "the Man doesn't fight for peanuts."
(Granted Lacy is injured right now but when he returns he'll be looking for a quick titleshot that he thinks he might win. A good chance for Mundine to get a good name on his record if you ask me)
(Not sure Bute will be interested in this fight when he most likely become champ though
(An overprotected guy with a perfect KO record who also gained all his amateur victories by KO, if Mundine beats him he would definately get more respect than by beating guys like Nievas)
(A strong guy with an unbelivable chin who keeps attacking for 12 rounds non stop and who is in another league than Nievas)
And I could keep going, what about Froch, Tsypko, Beyer, Berrio, one of the Greens, Braehmer, Inkin a.s.o.?
Edit: Come to think of it, what about a rematch against Siaca, it would still be a lot better than Nievas.