I also believe that one is better off funneling more money into lenses than into camera bodies......that is, provided that the lenses offer an appropriate use value.
However, the 200 f/2 IS is one exceedingly expensive lens. There are significantly more practical and cheaper ways to get high quality and fast 200mm. As mentioned before, there is 200 f/2.8 and 70-200 f/2.8. Even the old 200 f/1.8 could be found for much less money. Need more shutter speed ? How does ISO 12800 grab ya ?
Ok, I sold my 40D while I'm here in Europe. Prices are so expensive here I made out, and my friend made out really well. I'll possibly sell the 5D while I'm here too, and then I decided to dump a mountain bike as well. Depending on the price of the new 5D, I'll only need to come up with another $400 or so. Problem solved!
Hmmm ... so you decided to go for the new 5D body? I didn't do an exact count but a quick squiz through this thread gave me the impression of opinion being heavily in favor of the lenses! Was your OP a slightly rhetorical question or did you find the lure of an unknown new body just too much to resist?
It will hold its value more, too, so if you don't use the lens much in a year, you can sell it and pick up the 1D's replacement and still come out ahead...
But what do you need to grab the shot? If you're into high ISO, then the 5D's replacement might be a good move - but from every sample I've seen, the 200 f/2 is tack sharp wide open with IS as well. If nothing you are shooting really demands the newer features of the 5D's replacement (and thing hard, do you REALLY need all those extra features when your 40D and 5D can still snap a great shot as well?).
The 40D is still a great camera - it might be worth selling that and getting the 50D if the higher ISO is something worthwhile for you.
The 200 f/2L IS is probably going to be more expensive... but
You have been given all possible options: buy the glass, upgrade the bodies, swap some glass and do both. I would simply like to say: when the new bodies are out, look at the pics and reviews. If you can, borrow them and go shoot some pics. You will know what's right by then. A camera body does 3 things for you: the IQ, the pics it lets you take, the feel. If after shooting you still don't know if you want either or both of them, you'll have your answer too. I know that that is how I will decide what to do with my 40D: take 50D and 5DII out for a spin, and then make large prints. Decision will be clear by then.
Funny. I just remembered that I recently replied to this post. When i replied I had no thought of buying the 200mm f/2 and the new cameras hadn't been announced. Yesterday i bought a 200mm f/2 and I'll be upgrading my 40D and 5D to the 50D and 5D Mark II by the end of the year. Go figure.
