I know that The Undertaker has beaten Edge already at WM 24, but just remember he's really involved in a feud with Chris Jericho. Since, we're 100% that Triple H will be in a WWE Title at WM 26 (against Sheamus or HBK), I really believe that Edge would challenge the WHC at WM 26.
SO, why wouldn't make it a Triangle feud between The Undertaker, Chris Jericho, and Edge?
And with the fact that The Undertaker will take time off, so why not make it a triangle feud, so when The Undertaker taking his time off, Chris Jericho and Edge can have one on one rivalry until one of them drafted to Raw.
And about Chris Jericho being a clown, I completely agree. That's why WWE should make him stronger than ever and draw bigger geel heat. I think the only way is making him the winner of Elimination Chamber and win the WHC by screwing The Undertaker out of the match, such as attacking him before the match. And the fans would really hate Jericho that time. Not only that, The Undertaker would have his rematch at WM 26 and put on one of the greatest WM match of all time with two great performers, Chris Jericho and Edge. And while we all know Undertaker would win back the title at WM 26, Chris Jericho or Edge can win the title at Backlash, and after that The Undertaker taking time off. That would make a way better story.