Doubt it if the story will stretch that far. First of all, it has become boring to see the same story again and again. It was a classic rivalry in 1997/ 98, and gave us incredible matches like Mania 14 and the inferno match, with one of the best story-telling that we've seen, that too from two of the best gimmicks. In 2003/ 04 again, when Kane buried Taker's human persona, it was a good story although the match at Mania 20 was not that good. I don't think Kane is at his athletic best now, and honestly he won't be able to give a great match at Mania. Taker, on the other hand, despite age and injuries, is still delivering match-of-the-year-worthy performances at Mania as he did with Batista, Edge, Shawn Michaels and again Shawn Michaels. To keep up the standard of those matches, he should face somebody who is a better wrestler than Kane. If the story stretches that far, it would become too boring. Its boring now anyways to know that once again, its Kane who took out Taker and then Taker will return for his revenge. We have seen that happen many times before and there is nothing new in it.
I'd have preferred seeing Swagger as the one who attacked Taker, so that we could have seen a fresh feud for Taker, moreover Swagger deserves the push and he can work well with Taker in the ring. Seeing Taker and Kane again is like seeing what we have seen 2836128768327649874987 times in the past. I like them more as brothers of destruction when they intermittently team up to kick collective a**es of some bad guys.
However, the one good thing that has happened with this is that Kane has finally been given the title. Its something that he always deserved, that he was always worthy of, and something that should have been given to him many years back. I still remember his 24 hour reign as WWF champion in 1998 when he won it from Austin and then lost it the next night. That sucked - he should've held it for longer but the attitude era was all about pushing Austin and making other (including some better) guys look bad in front of him. After that, there were many opportunities when Kane should have won the belt but he was never given it. Even his ECW reign was short. Now, he is given the WHC belt at a time when he is not at the peak of his career and can't deliver such good matches anymore. So you'd expect that he won't hold it for as long as Mania. However, I do hope he will hold it till beyond Summerslam. While Taker is most probably going to return at Summerslam, he might not compete. It might just be a last minute segment like it was at last year's Summerslam when he attacked Punk. If Taker is not fully healed from his injuries, then he might just return to attack Kane similarly, at the end of his match (with anyone - could be Mysterio or Swagger, for example). The next few weeks we'll have some promos and build-up with Taker's mind games, giving Taker more time to heal from his injuries and allowing the story to flourish while Kane holds on to his belt. At the next PPV, Taker can beat Kane to take the belt from him and carry it till beyond Mania thereby having a long title reign, where he'll go 19-0 and then maybe drop the belt to somebody at Backlash so that he can take his regular time off to heal nagging injuries.