I can't pretend to have the knowledge required to understand the paper, but from the looks of it, the reactions to it, and the guy's credentials and past work, it sounds like it's a very serious attempt and I hope it pans out.
The proof, if verified, will also probably open a lot of doors into new areas, and says something important about human creativity. That is, you can't simulate it with a classical computer. At least, that's how I understand it. The implication is then
that the brain is a form of quantum computer, which has been proposed for a long time now, but it certainly couldn't be simulated by a classical computer if my understanding is correct.