This one has been years in the making and you have to believe that WWE will make it happen at some point. It could even be as soon as WrestleMania 32, but early indications are that it will be The Rock vs Triple H next year. That makes us think that they'll do Reigns vs Lesnar at 32 and then the big one at Mania 33 - Rock vs Brock. The reason it makes so much sense is because both are commercially big in the mainstream. Putting them against each other is a big deal to the casual audience, and indeed the purist wrestling audience. Just like Rock vs Cena put a pop culture light on WWE (with the highest grossing PPV ever, back in 2012) we can expect a similar boost to the business from Rock vs Brock. There's also a nice full circle narrative of their match from 2002, where a rookie Brock beat Rock out of the WWE. The original plan was for this rematch to take place at WrestleMania 30, but injury stopped The Rock from shooting an angle the night after Mania 29. WWE are just waiting for the opportunity to re-book it. As for who wins this time, it makes sense for Lesnar to go over, given that he'll definitely be the one working future dates.