The buzz is out that there's two new full-frame bodies coming from Nikon at once. People are concerned that it's a bit wierd that there's to be a D4 and D800 released at the same time, but not if you think about it from the video standpoint. Nikon is still playing catch-up to Canon in this area, so look for the D800 to be a "5D mkII fighter" with a big sensor.
I wonder what this will mean for the long-awaited D400? Will it fall in the 18-20mp range as anticipated? Will I even care, being that there will be a plethora of available D700s dumped on the market once the D800 lands? Mmmmmm, D700 deliciousness at discounted prices! Yummy! I can't wait for August!