I've been calling Brock to return at Mania since his loss to Overeem. The fact that there was complete radio silence on this until the day before WM is pretty awesome, since it means only Vince, Brock, Steph, HHH, Rock & Cena know, they've been keeping a tight lid on things cuz the dirtsheets haven't said a fucking thing.
This is the perfect way for WWE to have the main event be a schmoz with neither Cena or Rock having to do the job(a big sticking point in the company). IMO, the lights go out with both men on mat & come back on with Brock in the ring. Double F5's and leaves them lying with Brock standing victorious as they go off the air. Can't think of a greater cliffhanger for next night's Raw(that happens to be their biggest of the year) and gives legs to Cena & Rock to have a three-way match at Summerslam &/or WM29 as planned. Brock's such a massive name in combat sports, this is the type of thing WWE has been salivating for a while now.
I don't see them involving Brock with Taker if only because I don't think Brock can work well enough to compensate for the current physically deteriorated state Taker's in. They're also pretty determined to have HHH/HBK be the backstory so they can have a bout together at next year's Mania too. The Streak will only be defended against guys who can work GREAT & protect the shit out of Taker and bump like hell for him. Brock(if he's not back fulltime, is therefore not the guy). I think next year, if Taker's still able to work his Santa Claus schedule(1 day a year lol), I think Barrett, Ziggler or Punk get the nod.
Mark my words, if this happens(could be a smoke screen since Batista's in town too) it'll 99% be in Rock/Cena and leave both men laying. I've also heard a Cena heel turn is possible, but his merch sells amazingly and is too great of a cash cow to give up.....
Also wouldn't be surprised if WWE does something ridiculous like just book a showdown between Batista and Brock. Their booking is TERRIBLE for the most part and they might do something out of the realm of commmon sense.
Anything involving Brock's return is ALL ABOUT the next night's RAW rating coupled with selling tickets in NJ for next year's Mania.