I'm in the camp that can't see the 5D MkIII being released before the 1Ds MkIV (or whatever it may turn out to be). Yes, it is lacking in frame rate and speed of focus, but in low light in one shot mode, it out performs the 7D. I've also heard of similar complaints about focus in the Nikon camp, plus test shots seem to indicate that there is very little difference in noise levels between the D700 and 5D MkII (although I haven't of course done a side by side test). There are differences in the noise in those shots, but it's more about the look of the noise than the actual amount and then it is down to personal preference on which you prefer.
I have two work colleagues who are interested in photography, one was a Sony user, the other is a Nikon user. In the past month or so, both have been strongly considering a switch to Canon. The Sony user actually bought a 7D a few weeks ago and is now raving about how good it is (although it was before the A77 release). He also likes the choice of lenses, even though he's struggling to choose which ones to get for his needs. The Nikon user has decided to wait on the playing out of the current Nikon rumours, but he has said that if he had his choice again, before buying into the Nikon system, he would have chosen Canon. He considers that Nikon have made a bad choice on limiting the sensor resolution to 12MP for so long. He looked into the D7000 to replace his D300s, but didn't like the idea of the drop in build quality. He's also flip-flopped between crop and full frame, going from the D300 to D700 and back to D300s, because he found that he didn't have the reach on his lenses with the D700 that he needed. He of course wishes he kept both, to have a similar combination to me with my 5D MkII/7D combination. As he said, having the extra resolution isn't always necessary, but it gives him the flexibility of cropping when he needs to. I suppose it's a case the grass is always greener on the other side, as I've thought about Nikon in the past for low noise, high ISO. The 7D may not match the D300s, but I feel it is pretty much on a par with the D300 and I have the extra cropping factor if I need to, because of the higher resolution. With my old 40D, I had to upsize for submission to Alamy, the 7D stopped that and even though Alamy have reduced the submission limit, I have room to crop and still be ok. More images means more potential earnings (subject to sufficient quality), which means more gear I can afford, not that I could ever make a living from it