Nikon today pre-announced that they will be producing an 800mm f/5.6 lens. (It's now the policy on my sites to use the word preview or pre-announce when no details are made available on an upcoming product.) Other than focal length, aperture, and a note about dust and water resistance, no details were released. We don't know when, how much, how many, minimum focus distance, or any other of the details that are usually made with a lens announcement.
So why pre-announce? Apparently the lens will be displayed at the British Open later this month, that's why. Now why would it be displayed at the British Open? I suspect that one or more pre-production copies are sneaking into Britain for the Olympics, at which point the lens would be "outed," so might as fess up to its existence. Strangely, the Olympics aren't mentioned in the press release; only the British Open and Photokina. Still, if that's a working lens, I'll bet bottom dollar someone will get a chance to use it at the Olympics.
It is also curious that the one line offering any tangible details ends with "...and will be fully compatible with Nikon FX-format cameras." I realize why that line is there: it's an FX lens, after all. But by phrasing it that way, Nikon is going to send another shiver of paranoia to all the DX users in the world, users who aren't exactly feeling loved by Nikon at the moment. The line could have read: "...and will be fully compatible with Nikon's complete line of DSLRs, both DX and FX format."
While the press release also mentions that the specification, finish, and design are not final, the photo released with the pre-announcement suggests that while Nikon has changed its tripod mount arrangement, it's still likely to be highly compromised in support integrity. Balancing a big, heavy lens on four small screws in a very narrow area is a well-known design liability of existing long Nikkors, and this new arrangement doesn't look like that has been addressed at all. I'd show you what that looks like except that, as usual, the NikonUSA subsidiary's Web site doesn't yet offer the image to the press (or even have the press release) as I write this.