I have a 6D on pre-order...
It's perfect for me. It will go very well with my 60D. I shoot some sports, gigs and portraits. The 60D has always been perfectly fine for my sports needs so I can keep it for that. The 6D will be perfect for portraits and great for gigs since I only really use the centre AF point anyway.
For me, buying a 5D Mark II would be pointless, as buying CF cards to replace my SD cards would put me around the same price point as the 6D, if not, more. The 5D III, although perfect, is out of reach.
I'm not a professional, I shoot and earn money from it, I shoot for fun, I'm going to college for photography. The 6D is perfect for me, in absolutely every way. Yeah, I would have liked the 7D's AF system, but 9 points doesn't bother me, I wouldn't care if it only had the one point in the centre - that's all I pretty much use.
It's been said that you get what you pay for. You're never going to get exactly what you want, a compromise has to be made someone. If you really want better AF then save your money for a few extra months and get a 5D Mark III. Is it really that hard a concept to understand?
I don't care that it has SD cards over CF cards, in 4 years of using a DSLR I've never had an SD card fail on me. Class 10 SD cards are perfectly fast for practically anything, my 60D's buffer clears quickly and the 6D should be fine.
Canon didn't mess this up, it's an entry level full frame camera.
Treat full frame and APS-C sensors independently of each other.
650D - it'll do pretty much anything you need but it's a simple camera with a few cool features to appeal to consumers.
60D - more robust camera than the 650D, better built, better features, not necessarily aimed at people looking to just take snapshots.
7D - top of the line, professional features, built like a brick.
6D - it'll do pretty much anything you need but it's a simple camera with a few cool features to appeal to consumers.
5D Mark III - more robust camera, better built, better AF, less gimmicky, built for professional use.
1DX - Top of the line, if you want the absolute best then this is what you buy.
I think some people are just too cheap to admit that the camera they want is a bit more than they would like to spend.