My D200 plate worked on the D300, but it doesn't appear to fit the D700 -- just from looking at it the camera shape appears to present a bad fit.
While this may seem awful, if you get in a pinch and absolutely need a mounting plate, you could Dremel off the flanges that go above the flat surface of the mounting plate. (The part that nestles the lens mount on the D200/300. It would look bad, but it would be a last-ditch solution that would be attainable if all else fails when its time to leave for the trip.
I assume you are asking about an Arca style base plate. If so you might want to consider the the RRS MC-L generic L bracket as an interim solution. I have used mine with an F4, FM3a, D70 and D200 and plan to use it on my D700 until I a proper L bracket for the D700 is available. Using this bracket with the D700 (and D200, D70 for that matter) you may not be able to open the door on the left hand side (looking at the camera from the rear), but for me that is not an issue.
Well, to be perfectly honest I haven't tried that. Given the number of attachment points along the bottom of the L-plate you could mount the plate so that there is a gap between the side of the camera and the L-plate to allow the door to open wider which might work.
I'm number 1 at Berger Brothers and one of the first NPS orders in the Nikon system so I'm hoping I can quit thinking about all this and start using it pretty soon - mainly to see where I stand with existing lenses such as the 28-70 2.8 the 70-200VR and the Sigma 120-300 2.8.. If the Sigma does a nice job I will be ecstatic because I will slot it in where the 70-200 used to fit.
I also ordered the SB900 and I'm curious to see if Nikon goes ahead and sends me one.
Early adopters may want to consider the Wimberly generic camera plate. That should fit anything. It might be a handy thing to keep around for these once a year or every other year events, tiding you over until you get a custom bracket. I'd rather do that than hack up a good custom plate that could then be resold.
I've attached the RRS MC-L plate to my D700. There are several mounting holes along the bottom of this plate. It can be mounted so that the vertical part of the L is snug against the rubber door blocking access too the connectors behind the door. I have it mounted with a small gap between the door and the plate so that I do not mar the camera. If you mount it to get the largest gap between the door and the camera you can get the door open but it rubs against the bracket and is a bit squished.
I'll be glad when my custom bracket arrives from RRS, even if it is a bit on the ugly side.