You come out with some rubbish flake. Sony make chips but don't design them! They are based on Kodak research who design them and then licence the design to Sony. To say the D3 was a lucky break is utter rubbish, and could be regarded as very brave by Nikon as mags always push for more pixels per chip/sensor. A few weeks after the D3's release a firmware update was provided which included the reference to the D3x, so it appears Nikon already had the sensor for it.
As to the question posed by the original poster, I would stick with Canon if you are use to the system and have a lot of lenses.
LOL that's quite funny! I can't find any evidence on google to show that Kodak are designing the CMOS sensors for Sony, I can however find plenty of evidence that Sony designed the latest Exmor sensor themselves.
"a new type 1/2.5 CMOS image sensor "Exmor" for use in camera enabled mobile phones that leverages Sony's proprietary formation technology to realize the industry's smallest unit cell size (1.4µm), and the industry's highest pixel count (12.25 effective megapixel resolution)"
OK you say that Nikon was very brave launching a camera which bucked the trend for more megapixels, but I don't see it like that. I see the D3 as being Nikons answer to Canons 1D series, it had more MP but you show me the evidence that Nikon marketed this as being for the purpose of low noise when it was launched. So far as I can see, and I clearly remember the launch, it was the opinion of users not the manufacturer who highlighted this 'hidden' benefit, and thus I think it's reasonable to say it was a lucky break especially when the 1D MkIII's focus issues are taken into consideration.
The D3 contained Nikons first in house produced sensor, there is no doubt in my mind that this sensor would have had more MP if Nikon had been able to squeeze them in and get a decent yield.
The result of what happened change the way of thinking of certain users, but that thinking was certainly not widespread prior to the launch of the D3 and I don't see any evidence to support that Nikon was thinking outside the box in it's design, I see a logical & progressive development of the D2x
This might be a better link as the last Exmor one was a Mobile phone:
Sony 24 Megapixel CMOS : Sony announced the development of a 35mm full size 24.81 effective megapixel, ultra-high speed high image quality CMOS sensor designed to meet the increasing requirement for rapid image capture and advanced picture quality within DSLR cameras.
I was a Canon user up until January of this year when I defected to Nikon. The reason for this is simply down to product failure, in the space of two months the grip on my 40D has decided to strip the thread on the wheel of the grip itself which rendered it useless as it could not be removed from the body nor tightened up again...... Then just weeks later and only two months out of it's 12 month warranty my lens decided to show errors on the body on anything under f5.6. No fix by Canon there.
They did fix the grip problem though, after leaving me with the use of my old body for 5 weeks.....
Now don't get me wrong, I was extremely happy with the images that I got from my 40D and to be honest it took me some time to get to grips (no pun) with the Nikon. As far as image quality is concerned, both camps are capable of really top-notch photographs.
Nikon do have a 2year warranty, which if Canon had the same would have meant a free repair on the lens! Think about that before you spend your hard earned.....
Funny that because my battery grip did exactly the same thing and had to be cut off the camera body, it's caused by overtightening and is easier than you might think. At the price Canon charge for the grip they should be better engineered than that.
Both systems can have their problems though it's not just Canon although as you say Nikons 2 year guarantee is worth having.