I have already preordered the 5d3 but the sample images failed to impress me in some ways. I would have liked more megapixels. I did try comparing the D800 sample images and one of the things I couldnt get over is when pressing the 100% button how much more detail I was getting in the Nikon shots. Extra zoom in on detail, seemed sharper and clearer.
I know that the jpg samples are not anything good to go on... Some of the Canon ones improved no end with a small amount of sharpening in Lightroom for instance. Whereas perhaps the Nikons had already been severly edited.
The fact that so much of the marketing spin on specs for pro cameras apply to jpg not raw bugs me. I dont care at all how many stops blah blah on jpg... I want to know for the raw. I shoot raw, I edit raw... thats what needs comparing... I dont care if you give me 14 stops of noise better than Nikons off camera jpg in your off camera jpg, especially when your jpg production ripped out all of the details to do so...
I'm not a pixel peeper... well I am... but not for sake of it. Most of the work I have sold recently has been as 30x20 prints and I would like to go bigger. Obviously I would love a Phase One on a Hasselblad but thats probably never gonna happen... but if ff dslrs could nudge themselves towards what the medium format cameras do in some aspects that would be the way I would like to see a line or two develop.
I think, to oversimplify to illustrate a point, so please dont take offense at anything thats said that may be a little unfair)... That some of this megapixel thing comes from how long you spend with and keep selling the same image for...
For a wedding photographer, You probably will only print over 16x20 very rarely and once the bride has chosen her shots and youve supplied the prints you will rarely see those shots again, it is extremely unlikely you will come back to edit the same images in years to come.
For a landscape photographer, you will go to places that you will never return to and will end up selling and sometimes re-editing some of the same images for years. The shots a landscape photographer makes his money off arent usually the ones he took last weekend.
So for a wedding photographer smaller mp, less editing, fast throughput are great.
For a landscape photographer as much detail captured while you are there as possible, more editing is viable in a scene that is worth it, re-editing with more up to date software down the line can improve an in image. Printing techniques and formats change and can allow larger and larger pieces to be made from your work. Some of those extra pixels may come in use in years to come. Some noise introduced by making those pixels smaller may be removable in years to come and more detail retrievable... Improving software and algorithms can modify all the pixels you have but they cant help you about the ones you didnt capture.
One obvious previso there is that as the higher mp mustnt by a knock affect on other aspects of the shot add blur to your source images, that will really screw you up... though software is even starting to make inroads into that apparently... "unblur" alogorithms... but thats neither here nor there...
So basically, yeah, I want more megapixels. 30mp on the 5d3 as opposed to 22mp would have been nice. The fact that the D800 has over 1 and half times as many pixels irks me a lot more than if it had a sixth or fifth more...