So, I've gone an ordered a 1080 non-Founders.
Did a bit of research last night and here's what I know.
I'm UK btw so UK related info.
I will also caveat that I have a fully built gaming machine with VR sitting here doing nothing while it waits for a GPU so I'm erring to the "not waiting too long" side of things. =p
Will also say I'm not really interested in Founders edition so ignoring those.
So eBuyer have a bunch of 1080's on there for preorder with prices, expected date is June 30th.
However Asus have this on their website :
http://pcdiy.asus.com/2016/05/this-is-the-asus-strix-geforce-gtx-1080-pascal-on-another-level/
Expect the ROG Strix GeForce GTX 1080 to be available starting June 4.
June 4th??? What's this!!
And it seems
Overclockers UK have the Asus Strix on their site, I couldn't find any other UK suppliers, and it's £620 though.
However although price is up there, it looks like the Strix itself is also right up on the heirarchy of 1080 cards, complete with 3 fans and crap flashing leds =p :
(these figures are from Asus though so....)
http://thepcenthusiast.com/asus-rog-strix-gtx-1080-graphics-card/
Also, and I'm still trying to figure it all out, this Asus Strix model seem to forgo one displayport for a HDMI which seems to have been done specifically with VR in mind, say you already have a HDMI display which kinda makes sense.
I think one HDMI only might be problematic for some if adding VR, while only 2 DisplayPort might be problematic for others? Dunno.
So I phoned Overclockers and they do indeed say "according to suppliers" they are getting the Asus June 3rd (along with some KFA2 models. Other cards they expect June 17th (so not even that long really).
With Overclockers preorder they take the money right away though which really put me off given nothing re the date is guaranteed at this point.

But on speaking to them they tell me I can get a refund anytime with no penalty, which I;d be tempted to do if the Asus ended up June 30th or something.
And so that date has been enough to clinch it for me so I've bitten the bullet and pre-ordered an Asus Strix. My poor bank account. [sad]
Also worth noting the Strix has extra power connecter and watt requirements over a standard 1080. Can see it on the right.
Not affiliated with OCUK in any way! =p