still, good on him. always good to see people trying new things. pushing tech that has just been brushed over and disregarded, who knows, maybe they missed something. sounds far-fetched atm, but so did many other breakthroughs.
also, its not that big a deal switching from polygons to voxels, as you say, voxels are just 3D pixels, all you'd have to do is "render" the poly mesh to voxels...
another thing. ok, so yeah, it wouldn't be unlimited, you could only have as many points as you could fit into memory, and you would need alot of memory, but keep in mind, its not the AMOUNT of memory at the moment that's the bottle neck. its memory BANDWIDTH, so even if you have to have 32GB of memory, if his search algorithm is really good, he would only really need enough memory bandwidth to pull one screen worth of pixels out every frame! and say you were doing it as cloud based gaming (like that thing where it renders on a server somewhere and then streams the result to any really underpowered device) if you were doing that, you could just have one level loaded into ram that could serve EVERY PLAYER IN THAT LEVEL. they could all search the same level in ram! limited use of memory bandwidth is more important that use of memory capacity at the moment.