...Your shot is absolutely incredible....
When I follow the links you provide, I am only offered the 1024 pixels as the largest. Maybe a setting on your flickr account.
BTW, the image was not mine, it is the nikonrumors flickrs. These photos were available from the main page http://nikonrumors.com/2012/03/27/full-size-nikon-d800-sample-images.aspx/
Right now, I have some reserve toward my yet-to-come D800 purchase. Looking at the D800 samples at the full resolution and 100% crop, I see a lot of noise in the background bokey even at ISO 100. At this point in time, I am still considering my options and I may decide to get a D4 instead. I still haven't seen a single full rez D4 shot yet so I find it hard to figure what to do.
Edit: I just found full res samples.