If you actually, and sincerely, require more than 12MP, then you should probably be able to write off your equipment as a business expense.
Buying what you can, versus what you need, is what the jumbo MP crowd is appealing to. Other than a professional billboard photographer, who would need 46MP, yet alone 64MP? If you have a $30,000 lens, then the need has no relevance. Obviously, money is no object and the competition requires you to grab every advantage you can. Is that you? Are you a successful professional that budgets for equipment? If you're not successful, a new camera with more MP isn't going to make you solvent.
It's easy to get caught up in the race. The D600 is a good bargain and has more resolution than I'll ever need in my entire life.
I'm a hobby oriented photographer. If I made money using a camera, I might be able to justify 24MP. After that, it's just "mine's bigger than yours".
Actual photo results are what count. Not the equipment you can afford.
Be sure to read my disclaimer below.
You knew this was going to happen, just a matter of time. Really, I feel the ship came and went and Canon wasn't on it. Wait until they get a load of the processing and storage required for the massive files!
So, what is next? I shudder to think. The d800 has taxed my computers to the limit and obsoleted two of my systems. It is eating my storage space as fast as I can pour a glass of water and they are pushing the envelope even further.
actually, the rate of data storage and higher processing speed computers have kept up. With the USB3 connection and the current generation processors keep up well with the D800.
I can upload the pictures as quickly as my D700 with the USB 3.0. Luckly, my notebook was 4 years old and worn out, so, it was an excuse for an upgrade, but 500 dollars buys a nice notebook nowadays.
Art, you just have to be more liberal about not saving the mediocre shots. I actually like that about it. I have 1000's of 8 Megapixel photos stored that I will never use, and for what? I am only keeping what I feel is a good, or a possible sale shot now, but still, it will add up in the long haul. 46 is un-needed for most people - I mean really, but that is just my opinion.