Lol, you'd better order that 1080 now then.
Going from a 970 to a 1080, you won't see much in the way of a 'frame rate difference', but you'll be able to apply more detail and over-sampling. You'll get a cleaner image overall and overcome some of the low-resolution aliasing that VR suffers from.
I was a bit underwhelmed by my 1080GTX in ED to be honest - I traded up from a 780GTX, so I was expecting a big jump, with the 780GTX being effectively similar to a 960 and so well under the minimum VR spec.
But, given the frame rate stays pretty much the same due to ATW, after I plugged in the 1080GTX, I saw a little less judder (nice), and could apply 1.3x oversampling in the debug tool to improve the image (nicer). Other than that, the 780GTX was running all Ultra settings anyway. So it didn't FEEL like I got what I paid for the 1080GTX. Same went for Eve:Valkyrie.
However, out in 2D land, Skyrim, GTA and Warframe all went through the roof. Liquid, butter smooth with garlic and all with the gpu hardly breaking a sweat.
In ED I suspect my cpu is holding the 1080 back a little and there's more headroom than the Debug Tool's HUD would imply.
I haven't overclocked anything yet.