Just got my D600 earlier this morning. So far, I've put it through some tests and the handling seems ok (I still have some menu settings to play with though). Some annoyances (since I am used to my D90): they switched the zoom-in and zoom-out, and you can't use the rear wheel to scroll through images unless you're zoomed in. I think issues like that make it difficult to use both at the same time, so I might be "forced" to get a D7000. Oh well.
Anyway, autofocus seems fine, the AF sensors do cover a small area but I haven't found it to be a big deal so far. The AF seems to work pretty well in lower light, certainly much better than my D90.
Again, haven't noticed any color casts on the LCD (it seems pretty accurate when comparing to the original source), but since the screen is supposed to be the same as the D800, it might just be something I can't see.
I'll have to look at the images to comment more on the high iso quality, and I'll need to upgrade my photoshop to work with the raw files, so I don't have any comments on IQ.
I completely agree with your post. Also coming from a D90, some of the current controls are backwards from what we're used to. The playback button from D90 is now the menu and I actually keep accidentally pressing the menu to check out the photos...