I am optimistic about the sensor performance. I think (or rather I hope) Canon felt the need to cripple the AF in such a spectacular manner (at least on paper) because the IQ will be at par with 5DIII. Can dream, can't I?
With that said, I think this body will be under USD 1800 sooner rather than later and expect to see the kit below USD 2500 before Christmas (assuming the camera is released). At those levels I might consider it but I will definitely wait for the reviews. At USD 1500 I would buy it without giving it much thought (how bad the AF can be?).
It is interesting... If the D600 was a Canon I would have pre-ordered it (I never pre-ordered anything in my life). The 6D, on the other hand, is, as DP aptly described it: uninspiring. I have no problem waiting for the price to fall to a level I feel comfortable paying for a body.