Personally, I don't think we'll ever see Sting in the WWE in any capacity, nor do I think we'll see him in the WWE Hall of Fame, even if WWE does go with the WCW theme for their Hall of Fame next year. I don't think he'll be invited into the Hall because he never participated in a WWE ring ever, and if the WWE experienced a brain cramp and invited him I think he'd decline on moral grounds alone. By the way, for those people who posted in this thread saying Sting shouldn't enter the WWE Hall of Fame because he was never in the WWE, where the hell were all of you guys when I started the WCW themed Wrestlemania 27 thread a few weeks ago? I got little support in that thread, and now several people have come into this thread and others to agree with me.
Hall of Fame aside, I hate the idea of Sting ending Taker's streak. I hate the idea of anyone ending the streak, least of all a guy who, with all due respect, has thumbed his nose at Vince and the WWE for his entire career. Which is his right, mind you, but by making this choice, you cannot reward him by giving him one of the highest honors available to a guy in pro wrestling today. The honor of such an accomplishment should go to a WWE lifer, such as Cena, HHH, Jericho, or some up and comer that WWE wants to give a major push to. Sting, who would have to be finished with TNA by then for any of this to be possible, would only be <1 year removed from the "competition," has been anti-WWE forever, he does not have the right to defeat the Undertaker at Wrestlemania.
If Sting is going into the WWE Hall of Fame, I wouldn't mind seeing a Sting versus Undertaker match, but Taker has to win this match. He has to win it,decisively, or it cannot happen. A slap at the face at the Undertaker and all his years of loyalty, not to mention a slap in the face for all WWE fans.
And I don't think Sting's ego would ever let him finally jump to the big time, only to be unsuccessful. He'd only come if he could win, and he shouldn't, so he shouldn't come at all.