That is, that FX is the future for pro bodies. But let's look at the present: to shoot at 8 fps and close to my current average telephoto length of 1050mm (35mm and 12 MP equivalent, 500 f4 plus TC-14E on D300/s) I'd need a D4 and 600 VR and TC-14E (or my 500 plus TC-17E)which would put me at 980mm (cropped to 12 MP). Since using the TC-17E as part of my normal setup is unacceptable, this is a $16,000 upgrade cost - not $1,000. Even more unacceptable is the weight penalty - which is why I'd be inclined to look at Canon's 600mm IS II.
Now, I agree that a 24 MP FX body capable of 8 fps (with grip) could be the answer, but Nikon haven't put that on the table any more than they have pro DX (I think they have a far less capable camera in mind as "entry level" FX). Even then, I would have concerns about the viewfinder with my aging eyes. Until the cameras can shift the viewfinder magnification with an EVF this will be an issue.