If this holds, this is the discovery of the century.
If someone builds a useful NP problem solving machine, that will change the world.
Heck, most of the early groundwork in the computational field is probably more important than an algorithm that is useful only on quantum computers.
I was thinking of "if this paper is a contribution to eventually proving/disproving P=NP...", but failed to express that.
At that point quantum computing research will receive gobs of funding -- and our knowledge will absolutely explode.
You can debate whether it's the absolute top discovery, but this would be a lever to shift around the entire math and computer science field. If it wasn't a shaky paper, of course.
(Side note: until scott aaronson says otherwise, this paper is wrong. )