Polaris Replaces R9-390X and Below, Fury will remain in production.
All the Tahiti Rebrands and Hawaii Rebrands will discontinue production.

Navi is where it's at though.

NGM, Scalable GPU, Instead of one BIG EXPENSIVE CHIP that will have low Yields per wafer,
They will put 4 smaller Chips on a Single Interposer w/ NGM. As far as the PC is Concerned it's one GPU, when it's really 4.

So Top End w/ Be 4, Mid will be 3, Mainstream 2, Entry 1.

The videos above describe perfectly why this will save Money left and right.

nVidia's New Monster Chip, is selling for $5000, because they only get so many good ones per/wafer.