Despite being a huge fan of the Undertaker and his Streak, I've always subscribed to the idea that it should end. But, being something you can only do ONE TIME, it should have been used to put over the "next generation's" top heel. Imagine a heel that's slowly being put over, and then being scheduled to wrestle the Undertaker at WrestleMania, and then WHAM! He beats the Undertaker. This would put that heel over like nothing else--many wrestlers have won and lost titles--and this would have been an accomplishment that no one can match, replicate, or take away EVER. This would have rocketed the heel to the top, and he could be scheduled to tear through the roster until the "next generation's" up and coming top face (Daniel Bryan, maybe?) could take him down (it's important that this not be building for another notch in John Cena's belt, so to speak. That would squander the Streak just as much as this did). The potential to put over the next generation of top performers and set up matches that would have been remembered for a lifetime was all there.
And instead, the WWE wasted it all on BROCK LESNAR!? It's not even a question of whether or not he's good, it's that he's been in the WWE since 2002. Triple H and Shawn Michaels were some of the best performers in the history of the company, and the Streak would have been equally wasted if either of them had won because they are already over. The Streak was something to be used to put over someone new, not to add to the image of someone that doesn't even wrestle full time.
I understand that Undertaker's getting up there in age and he only has so many WrestleManias left. They may not be able to find that perfect up and coming heel and give him enough build up to justify defeating Undertaker. Fine, but if the WWE was going to use someone already well established and over to end the Streak, why didn't they use KANE!?