For a stills/video shooter like myself the 6D is looking better and better for every day that passes without a statement from Nikon that they will somehow remedy the obvious limitations of the D600.
I was a Nikon shooter back in the film days and I only switched to Canon because I got a used rebel for free.
After growing weary of the limitations of the rebel + the nifty, I upgraded to a 60D + 50 1.4 along with some old converted lenses. Having played around with a 40D belonging to a friend for a while, I thought the 60D would be somewhat similar, but I found myself somewhat dissapointed in spite og having spend countless hours researching the upgrade. I am currently entertaining the slim hope that the 6D will offer a better "feel" than the 60D but I know that I might have to go 7D or 5D to achieve that. ( 1. world problem, I know
I have been longing to go FF for a loong time, but seeing as the 5Dmk3 is way out of my price range, I almost jumped ship when the D600 was released. Until I held one in the shop that is.. and realized how limited the video mode is.. and remembered that the chance of a Magic lantern release for D600 is slim...
If you shoot mostly stills and happen to like the ergonomics of the D600 (this could possibly be vastly improved with a grip), it looks like a fine contender indeed. Even with my small hands however, it just didn't feel right (could be power of habit)
Anyways.. meanwhile, something "happened" to my 60D, and I am now without a proper camera whatsoever, trying to figure out if I can survive with my old Olympus e520 until the canon hits the stores, buy a 60D or a 7D (or even a D600-god forbid) and sell it when the 6D arrives... its hard to be so spoiled
Just pic up a 5Dc in the meanwhile. They're incredibly cheap right now and you'll get a taste of full frame.