As noted earlier this week, while people in WWE will deny it I can confirm that Sting has signed a deal with WWE but it’s to be kept a secret so not many people are being told about it. I don’t think Sting will be debuting at WrestleMania. If he does debut then it would be the following night on Raw to get things rolling for his match with The Undertaker at next year’s WrestleMania.
Sting noted during his Q&A in the UK this weekend that he had been watching Raw these last few weeks. That is notable because Sting was never someone that would keep up with the WWE product. Even during his WCW days he would not always keep up with everything else that was going on except for his own storylines.
As far as The Undertaker and his current storyline with Brock Lesnar, the production has been told to put together videos showing clips of their pay-per-view matches from 2002. The Undertaker has never beaten Brock Lesnar on pay-per-view so this is a good way to get the point across to the viewers that Brock Lesnar might have a legitimate chance at beating The Undertaker’s streak this year.
As of right now, the company feels that the WWE championship match will go on last at WrestleMania. As always, things could always change but this would seem to indicate that the company does plan on going forward with adding having Daniel Bryan win his match with Triple H and being added to the main event. If those plans change then I would guess that Brock and Undertaker would go on lasat.