This the main reason I haven't bought the a7rii and the metabones adapter doesn't really work well with Nikon glass at the moment. Commlite made an adapter but its sold out.
Nikon's full frame cameras had the ability shoot video in both Full Frame or DX (aps-c/super35) mode which was a nice feature if you had limited glass or wanted to get tight long shots given the price. Sony added that feature to the A7s/A7r and S-log which I find to be a bonus. I wonder how Nikon would have done had they added their own log vs the simple flat picture profile. Other than that, thats pretty much it.
I'm in that boat... I've waited a long time for Nikon to release something like this but for the price point I'm better off selling my gear and buying a used C300/5Diii combo or an A7R II. Spec-wise the D500 looks very promising but I've been wanting to upgrade to a FF camera so I really don't know yet. I would like to see how it handles.
I posted this on a forum a while back to see what others would think to such creation. I'm pretty sure Nikon did not come across it but would be interesting if they did. http://photo.net/nikon-camera-forum/00cfVk
True for my manual and AF-S lenses but not for my G series lenses which is a real bummer. My D200 has held up very well for my needs in the past but I'm long overdue for an upgrade with the rise of video abled dslrs and I've watched Nikon miss the mark over and over as far as what I was looking for. I've been lucky enough to have friends lend me gear over the years but I would have liked for Nikon to focus on a dedicated cinema camera instead of the 360 cam to really tailor to those who have extensive native glass. You can't always get what you want.