It's gonna be $399. I think people are forgetting the origin of the Neo. When Sony looked into 'slimming' it, AMD probably said for a bit more money, we can actually give you a large power bump on our new fabrication type.
Sony's plan is quite clever. Price drop the original PS4, to catch the price conscious and later adopters. Release a powered up PS4 at the old price to get the early adopter 'hardcore' to buy a console again.
Seriously, you $499 and up people are living in la la land. You are the only people in the world willing to pay that much for game console. And that my friends is no market worth serving as far as any sane console manufacturer is concerned. And Sony have proven themselves most sane this generation.