It's only the same price point if any partners bring out a card at $249. Neither the 1070 nor 1080 had release day cards that were cheaper than the Founder's Edition.
It looks like you still can't get a partner GTX 1070 cheaper than a FE, but I notice that ebuyer actually have quite a few partner 1080s now that are cheaper than the FE (although not significantly cheaper). If the GTX 1060 launches at $299 for both FE and partner cards, it'll overshoot all but the most expensive partner RX 480s. If they get partner cards out at $249, they'll compete with the higher-end 8GB RX 480s, which will use better coolers and more robust power delivery than the reference design.
We already know that you can get an extra up to 4% performance
by undervolting a stock RX 480 to remove the power and thermal barriers. Today's driver update brought
an extra couple of percent across a range of games. So even at stock clocks, a well-cooled partner card will potentially perform 6% faster than on launch reviews. Hexus managed to get a ~10% performance increase out of their reference card - largely by overclocking the memory (they only managed a 5% boost on the core but got 10% on the memory - a good indication that the RX 480 is bandwidth limited).
So it looks extremely likely that we'll see partner RX 480s that are > 15% faster than the launch RX 480 performance - putting them in the exact performance space that the GTX 1060 claims. Partner overclocked GTX 1060s at $249 would crash AMD's party a bit, but they'd be the *cheapest* GTX 1060s, competing with the *most expensive* RX 480s. Overclocked 4GB RX 480s could easily be the killer option in this market - perfect 1080p cards and competitively priced. Plus we still need to see what the RX 470 brings - at $50 cheaper than the 4GB RX 480 for only a small snip in architecture, they could shake things up even more.
So whiulst it will be interesting to see what nvidia manage to do with the GTX 1060, I can't help thinking that it's not actually trying to compete with the RX 480 directly, but rather trying to persuade the people looking at the premium partner 8GB RX 480s to spend just a little more on a slightly faster card...