I wouldn't claim to be any sort of boxing expert, but if Green won on points I'd be very surprised, unless he hurts Mundine badly enough early on that he's not fighting at his best towards the end. If Green wins, he will knock Mundine out or go very close, and I'd expect him to do it early. One good point I read recently was that Mundine, for different reasons, will be just as keen as Green for the fight to be over early. Mundine is out to prove his critics (and there have been a lot of them, for a long time, though fewer recently) entirely wrong by dominating the fight and winning it convincingly. It won't be playing to his strengths exactly, but you can expect Mundine to come out hard early on and go for a knockout.
Anyway, I think generally most people find it a hard fight to pick. For everyone who claims that Mundine will win it, there's someone backing Green, and several more who can't decide. There's no doubt that Mundine has improved a lot more than Green has in recent times, and I'd also say that Mundine is more of a natural talent, but Green has a whole career of professional and amatuer boxing behind him, while Mundine only has a few years. The Mundine of a couple of years back wouldn't have been able to beat Green, but now he's a lot better and it's going to be a good contest, one way or the other.