Since there is such a big gap in performance between Polaris 10 and Vega 10, I could definitely see AMD doing as much as 4 different SKUs off of Vega 10.
A 64 CU 1600 MHz version at $600 with water cooling. Performance roughly equal to 1080 Ti.
A 64 CU 1500 MHz version at $500 with air cooling (possibly without an official reference design cooler). Performance roughly 20% higher than 1080.
A 52 CU 1500 MHz version at $400. Performance roughly equal to 1080.
A 44 CU 1500 MHz version at $300. Performance roughly equal to 1070 (and thus 30-40% faster than RX 480).
This assumes that Vega 10 will have PPF (thanks Crisium) similar to Polaris. If instead it is similar to Hawaii (and Vega can thus fix the ROP/Bandwidth bottleneck of Polaris), then you could add 10-15% to the above performance numbers, and potentially ~$100 to the prices.
On problem with such a lineup is of course that it might not leave enough room for a smaller Vega 11 in the lineup.
I don't think any of them would have less than 8GB of HBM2 though. 4GB HBM2 would meant either two 2Hi stacks (I'm not sure SK Hynix even offers 2Hi stacks) or more likely a single 4Hi stack. In the case of the latter option bandwidth would be cut in half, which isn't really a viable option IMHO.
Or just drivers better tuned for gaming,
which is essentially what Raja said would be the case: