If you look at a famous painting, you don't wonder what brand of brushes the now-decomposing artist used. Of course, if you go to a painters forum, you'll see passionate debates about which brand of brush to use.
Only a poor craftsperson blames their tools, but a good craftsperson will tend to get better results with better tools.
I'm primarily a film shooter, even though outside of photography, I'm quite "digital". My tastes in cameras are best described as somewhat idiosyncratic. I like to own reasonably priced cameras that can be made to produce excellent results.
The Canon 5D Mk II is here. And I was right that Canon was waiting for everybody else to put their cards on the table before letting loose with the 5D. 21 megapixels (slightly less than the A900, but more than the Nikons), maximum ISO of 25,600, live view, and 1080p HDTV recording.
I'm a little scared about the A-series from Canon.
The A-series has represented a great Honda Civic (Or Toyota Corolla, which is the most recent car we've purchased) sort of experience. It's not excellent at anything in particular. It's not the smallest. It's not the most impressive. It's not the best in the darkness. But, at the very least, it gets you most of the way there. It takes decent pictures, has a decent user interface, and doesn't suck in any major way. And because it's utilitarian and not sexy, you don't pay tons of money for it.
The Sony Alpha A900 is out, with a full-frame 24.6 megapixel sensor with built in IS. I'm the sort of person who thinks that this, paired with a 50mm 1.8 lens, would be fairly neat. You can bet that Canon was probably waiting for this to occur before they announced their 5D replacement, tho.
Often times, I hear people talk about their cameras as if they are classes in one's college education. They don't want to get a newer camera until they are comfortable that they've figured out their current digital. I find that, as somebody who takes his photography very seriously, that I have a mental model for photography that I simply try to fit as well as possible into the camera that currently is in my hands, so this idea becomes foreign to me.
Despite my film-shooting bent, I do like to keep up with the digital scene as well. This is all rampant speculation based on the available facts, given that nobody's dropping any expensive loaner hardware on my doorstop anytime soon.