MSRP for the 1080 is only $50 more than the 980 was at launch and IMHO has a lot more to offer. Add in the rumored boost/OC ability and it should be a GREAT card, along with the 1070, for anyone not rocking 980Tis already.
MSRP on the non-FE cards, of course. I would hope the 1080 will be a better card than the 980, as that one was a particularly poorly positioned SKU. It was massively undercut by the 970, and really only got to command its price premium as the top card for 6 months before the Titan X shipped. Worse, in less than 9 months the 980 Ti came out with much higher performance and a barely higher price.
The 1080 should last much long. Given what nVidia is predicting about P100 availability in OEM systems, it seems extremely unlikely we'll see even a Titan product this year. Titan in spring '17 and a new Ti summer '17 seems reasonable, but that still gives the 1080 a year at the top. It's hard to expect more than that, really.