Since he left TNA in the early part of this year wrestling legend Steve Borden aka and better known to wrestling fans as Sting has been rumored that he'd be joining WWE to finally make happen the one dream match everyone wants to see. Sting joining WWE would mean that he could for the first time ever fight the Undertaker and not only that do it at Wrestlemania, which is a dream match for wrestling fans everywhere. However the road hasn't been that easy as most people probably thought that Sting would have been signed by WWE already and some may have even thought he'd be wrestling at this years Wrestlemania. To that point it just happened that time wasn't on WWE's or the fans side to leave proper time to build such a big and important match.
The in many ways said part about this is that some people within the WWE believe that Sting is already signed by the company but other know that he isn't/hasn't signed with the company just yet. To my knowledge Sting has yet to sign a contract with the WWE and the reason why I can think of is because they knew they weren't going to use him for Mania this year so they were in no rush. But right now the word going around is that their is a chance Sting maybe at Wrestlemania or maybe on Raw the next day which is when they would announce the match, but the only way to know for sure is to wait and see because as right now nothing is confirmed.