To the original poster..personally I say go for the canon.
And even if the Nikon fans adhered to their own logic, they too would agree on buying the canon... see the Nikon guys think that big 35mm format is old and antiquated, just like they compare it to old 35mm film. Now, the 30d isn't this type of useless, big, heavy, expensive, technology, but the 30d HAS a smaller imaging sensor(barely), is cheaper, smaller, and lighter than the d200. So as you can see, what the Nikonians feel is bad about the Canon 5d, they just plain ignore on the d200.
30d has less noise.
30d is cheaper.
30d is smaller.
30d is lighter.
30d 100mm lense = 160mm ...Nikonians viewpoint being this is better(not mine)
d200 100mm lense = 150mm
30d/Canon user interface easier/more intuitive(most will agree that have tried both)
d200 resolution not really an advantage
personally believe the canon lenses to be superior
most sports photogs use canon..white lenses(in my sport, motocross, over 90%)
many press going canon as well
the following is a quote from www.completedigitalphotography.com
Your camera salesman might try to pitch you on pixel count as a deciding factor, but this is really a non-issue. While the difference between 8.3 million and ten million may sound significant, in practical terms it's really not. The extra pixels provided by the D200 simply aren't going to give you a significantly higher degree of cropping possibilities, or improved image quality at large print sizes.
As you can see I am a canon fan. It started with a Rebel 2000 film cam, then an Elan 7E, then Digi Rebel, then 20d, now I have a 30d. I have used Rebel XT, and Nikon d50(cool for the price). I have always LUSTED for a full frame DSLR, and was dissapointed to find out that they(the affordable ones) were cropped version. I couldn't come close to affording the high end FF canons. When the 5d came out, I was blown away. I still can't spend the $$ on 5d yet, but I will, or I will get the next version of it. I fully believe in FF cams, I believe we are in the infancy of their development. Really they are not that expensive(5d=$2700 all day long). Remember DSLRs aren't that old. The canon d30 (not 30d) came out in OCT of 2000 for $3500. This is only 6 years ago. This was a slow 3.1mp basic DSLR, yet it was the firts affordable DSLR. To think that you can get a monster like the 5D magnezium, full frame, 12mp work of art for $2700 makes it a bargain IMHO.
This 5D is barely bigger than a 30D, not heavy by any standards. The image quality is amazing, as is the ultra low noise it produces. You think this is a dying breed? Are you kidding, it has only begun. Prices will come down, speeds/quality will go up as they have been, and Canons FF will be the only way to go for serious pros if Nikon doesn't man up. BTW, the small collection of lenses that I do have for my 30d will work great on a 5d(17-40f4L 50f1.8 85f1.8 and soon the 100mm macro). I'm sorry, but if you actually think that an APS sensor is as capable as a full frame sensor, then you don't understand the fundementals of photography. The arguments against FF sensors suck, "its harder to go long on a FF camera..yadda yadda". What about "its harder to go ultra wide on a APS camera"? A sigma 8mm fisheye yields a 180 degree angle of view only on a full frame camera. Theres always room to improve and Canon knows that there is a future in this larger format sensor size.
Both cameras are great, the Canon system is better, IMHO.