I'm pretty sure Summerslam main event is either Seth vs. Brock for the strap (honestly, THE dream match of the present moment, even more than Cesaro or Bryan, as Seth is simply the best guy in the company) or a triple threat with Roman thrown in, either of which I'm fine with.
Who do you guys think Brock's 'Mania opponent for next year is going to be? We were hearing Rock/Brock, but now it's looking like Rock/HHH, possibly in a mixed tag with the Rousey shit. Brock/Taker would be idiotic, as there's no reason for 'Taker to be the guy who gets the rub for his own streak. Brock/Roman 2 probably wouldn't be as good as the first one, but it'd be alright. Considering they're setting Brock up as a major antagonist to The Authority, do you do Brock/Rollins? That'd be a HELL of a Wrestlemania match, brother.
I'd also accept Orton/Brock, mainly because it'd be an awesome match, and Orton's one of the few guys with the kayfabe credibility to not be laughable in such a match, but that seems more like what they'd have Brock do for Royal Rumble to tide him over than his 'Mania match. Then again, Orton's the bigger star, and given the size of the stadium, maybe that matters more for WM32.
Edit: I am, of course, assuming that they're not going to have Cena do it - which they of course might, though I think Cena vs. Roman for the belt is a better use of both guys' time, and Cena giving Roman the rub is safer than having Brock use his one-time streak rub on a guy who might not work out, long-term, as THE guy. I also don't see any reality where they ever see Bryan as a big enough star to have anything more than a Summerslam match against The Beast, at best, and honestly, with how Brock wrestles now, I almost don't want to see the match.