Shawn Michaels and HHH didn't need the win either... but they sure made it look believable that they were going to beat Taker. Cena can do the same. In fact, Cena can make it work even better.
He is undeniably the biggest star of this generation and defines an era. The match quality doesn't have to be great for a match to be good. Take Hogan/Rock for example. Wasn't a great wrestling match, but the crowd, the story being told in the ring, and the emotion being poured by the wrestlers made the match what it is. Cena/Taker can be structured similarly, but for that I think Cena would have to turn heel.
Except Cena isn't Hogan. He had his match against the Rock and proved he just can't hang on that level. Though you have a point with a heel turn. That would easily be the ticket for that match to be good, but we've seen the WWE gunshy on that so I won't hold my breath.
As for HHH/HBK... HBK/Taker 1 and II worked becuase the build for WM25's match was just epic... that is how you build a match. They gave it a reason. Then career v streak... we knew HBK was retiring, but we all desperately wanted to be wrong. As for HHH/Taker's two matches... they were good matches but the build was terrible for the first one. The second had better build and was a better match, HBK's contributions cannot be ignored, but it was still one of those matches that accomplished nothing in the long run.
There are only two real matchups that have a possibility to work for Taker in terms of long term impact. Heel Cena/Taker... a heel cena could take the win and really use it to parade around and piss people off intentionally. And Punk/Taker... especially in a title v streak scenario with Punk's respect story still in play.... win or lose here, the story can continue. Punk loses and it can lead to him snapping and becoming more vicious. Him winning... well, he is the one guy that is big enough to face taker and would gain anything from ending the streak. It would be believable and it would legitamise his reign, despite the booking flaws of the past year. Especially if they can do it in a cell or cage or match where there is no dirty win really capable.
Those are the only real matches I can see that would work. But I don't see Cena turning heel anytime soon still and I don't know if the WWE would really do Taker/Punk this year and have him beat both the Rock and Taker in months. It would be massive and I think show that they are going to use part timers to build their full time stars. But I just can't see the WWE having Punk win over both of them with how they book right now.