Ok so here are a few thoughts.
First off, Cena will have the 'rematch clause' that every champion has for some reason, meaning he will lose to Brock one more time, that will be the main event for the next PPV.
If they are going to stick with Brock having the title until mania then Bryan is the one for me, as good as Reigns is I stick think that he's about a year away from being ready for the title. A Bryan victory would be an amazing rub for him and would be a logical closure point for The Authority claiming him as a 'B Plus player' The only question is whether or not Bryan is ready in time for a Rumble return as that's the only logical way of getting him into the main event at mania.
Dean Ambrose is amazing, he is the best of the three from the shield IMO and those two matches with Seth rollins were unbelieveable, the two sort of remind me of The Rock and Triple H, back in the 90's they fueded in the mid card over the intercontinental title before both moving up to the main event and feuding over the main title, I can see exactly the same thing happening with Ambrose and Rollins, two very talented men.
AJ And Paige actually have me interested in the womens division for a change, the only problem is my interest will inevitable drop once their fued has finished as there is literally no other female wrestler i care about watching, with the exception of.......
Brie and Nicki Bella, I have no interest at all in watching them wrestle, but if they fight, THAT would be worth watching, the storyline is good, the acting is not but it is still engrossing watching.
Then we have the mid card, The Miz Vs Zigglar is a very solid fued, The Miz is doing very well since his return, I know that the charactor was tried on The Rock a few years ago but it works better for Miz as everybody wants to hate him anyway, he is a very solid wrestler and i am enjoying the fued and the wrestling.
Swagger has improved alot, a very good match with caesaro on raw last week, a good showing against rusev at summerslam and another solid match with caesaro this week, doesn't sound right without zeb though.
Finally, Bray Wyatts win over Jericho was much needed and it was another very good match on the Summerslam card, He will be a champion one day, i am just praying that he doesn't fall victim to creatives ingenius.