Yeah, the more I think about it, it's a FF Rebel more than anything, with the SD card and Scene Modes.
But then i think about my friends with Rebels (well, mostly xxxD and one Kiss because he got it from Japan). Almost all of them have EFs lenses, barring a few with a 50/1.8 II (I even know someone with a 17-55/2.8 on an 1100D).
So if they upgrade to the 6D, yes, for them it's a genuine upgrade. But they'll have to get a whole new lens kit anyway.
With this release, Canon's banking on the fact that most of them won't bother changing systems out of 'subconscious loyalty' (or whatever you want to call it), ignorance that the D600 exists and is way better, or that they really like DPP being free (if they use it at all, i know most of my friends don't), or they're like my mother and have a genuine phobia of second-hand and won't get a 5D2.