Wow! while we were all arguing the merits of focus breathing, Nikon dropped a new lens on us! I don't have the cash for the 300mm 2.8, but that new TC lens would turn a 70-200 into a 140-400 f4 (or whatever 2 stops above 2.8 is... no time to look it up today).
So now that I was almost sold on the new VR2 version, I could have the older version (also very good) AND the new teleconverter for the same price. That's pretty compelling given that I would probably be using this lens on DX for the forseeable future.
DARN YOU NIKON! .... Now what am I going to do.