I can see a lot of scenerios happening
-Montreal screwjob on Punk since he's in his hometown and why not? He seems to be leaving legit.
-Montreal screwjob on Punk, Punk stays on saying he was screwed and wants revenge on Vince.
-Punk wins title for shock value, Mr. MiTB cashes in on Punk and wins title off him, so Cena can stay and Punk leaves without belt.
-Punk wins title, Mr. MiTB cashes in on Punk and wins title off him, so Cena can stay and if by some miracle Punk is to stay on, he claims he was screwed and wants the belt back.
-Mr. MiTB cashes in on Cena & Punk during match making it a Triple Threat and wins belt, so Cena can stay and Punk can stay or leave.
-Summer of Punk storyline repeat but I doubt this will happen since I heard Vince doesn't like to copy other promotions' storylines.
-Cena wins, nothing happens. Punk leaves legit, maybe could weaken Cena down on his way out before Mr. MiTB who will be Alberto Del Rio comes down and wins belt off Cena to set up their Summerslam WWE Title match.
I see the last option as being the likely one to happen. WWE never seems to capitalize on their hype these days and I doubt Punk & WWE will want anything to do with each other after MiTB is over or to be mentioned in the same words together in the case of a screwjob. I think he's leaving legit and WWE are clearly not happy with him with the way they've been booking him for the last year and with all the controversy he's caused lately.
-Montreal screwjob on Punk since he's in his hometown and why not? He seems to be leaving legit.
-Montreal screwjob on Punk, Punk stays on saying he was screwed and wants revenge on Vince.
-Punk wins title for shock value, Mr. MiTB cashes in on Punk and wins title off him, so Cena can stay and Punk leaves without belt.
-Punk wins title, Mr. MiTB cashes in on Punk and wins title off him, so Cena can stay and if by some miracle Punk is to stay on, he claims he was screwed and wants the belt back.
-Mr. MiTB cashes in on Cena & Punk during match making it a Triple Threat and wins belt, so Cena can stay and Punk can stay or leave.
-Summer of Punk storyline repeat but I doubt this will happen since I heard Vince doesn't like to copy other promotions' storylines.
-Cena wins, nothing happens. Punk leaves legit, maybe could weaken Cena down on his way out before Mr. MiTB who will be Alberto Del Rio comes down and wins belt off Cena to set up their Summerslam WWE Title match.
I see the last option as being the likely one to happen. WWE never seems to capitalize on their hype these days and I doubt Punk & WWE will want anything to do with each other after MiTB is over or to be mentioned in the same words together in the case of a screwjob. I think he's leaving legit and WWE are clearly not happy with him with the way they've been booking him for the last year and with all the controversy he's caused lately.