Of course it is overpriced and thousands are calling it that, maybe not here on tom's but in my top local computer forums people are laughing at the price and in Reddit UK people are going crazy over the price, so it has sure been called overpriced a lot.
Nvidia's announced MSRP for the non-reference was $379 which is near what a GTX x70 card has been selling for in all previous generation, i do not care how much faster or less expensive it is compared to last-gen's top performer, the fact is it is still a mid-range GPU, watch when the RX 480X, RX 490, GTX 1080 Ti, the new Titan and Vega all come to market in few weeks to few months, how the GTX 1070's price/performance will look like by that time, anyone who buys the card at the current price will feel ripped off and that they paid way too much for a mid-range average performer.
It is called an x70 for a reason, it is mid-range compared to what is coming in the next few months and should be priced as a mid-range card in this generation, comparing to previous-gen price/performance is not really meaningful at this point after the massive node-shrink that occurred.
I strongly believe the 1070 will come down to its $379 MSRP ASAP when the hype and craze slow down and people have many other options to choose from which will be very soon!