This is madness..
Ok a couple of facts that some folk seem to be ignoring.
There would be no Xenoblade Chronicles on 3ds without the beefier CPU. If it were capable of running on the original 3DS, They would absolutely release it on it, it's what? 50 million customers versus 0 current customers of the "new" 3DS. They don't profit too much on hardware and saying that it would be a way to sell the new system is insane, this is a niche RPG. You can't magically get games running on weak hardware, it just doesn't happen. No amount of wishful thinking or strength of will can achieve that, there is not enough power period.
We still don't know how much more powerful this new CPU will be but 5% is an idiotic estimate. The poster who even said that claimed he was pulling the number out of his ass and that he was only saying a random number for argument's sake. It's sad how some people were taking this completely random guess by a random forum poster as fact
There is still plenty of time to optimize the code, this is an early build so things are rough, it's premature to complain about framerate and whatnot. It would be wise to wait for the final product to make a fair and educated judgement.
Also take into account youtube video compression and that crappy quality screenshot. Not to mention that handheld 3D games always look like shit in captured footage. Compare
https://www.youtube.com/watch?v=RRlddPjcKUA to the game running on the actual hardware, it always looks much more jaggy in videos.
It's this or not having Xenoblade portable as an option at all. I understand the disappointment of people who already bought a 3ds but I don't think it's fair to say you'd rather have them not make this a reality.