There's really not much else to say about this lens that hasn't been said already.
I either own or have owned all the Canon "L" lenses (aside from the 1200/5.6 and new 800/5.6), and the 200/2.0 is second to none in all regards. In my opinion, sharpness (edge to edge), color and contrast of this lens is at the very top of the chain, possibly even topping my much loved 300/2.8L-IS.
Zero edge distortion even on FF. There is a slight hint of vignetting on a FF sensor at 2.0-2.8 or so, but certainly not an excessive amount.
AF is lightning fast and super accurate on my 1Ds3.
New IS is so effective I can't even describe it. With my other IS tele's, when IS is activated I can notice a slight bit of stabilizing even through the viewfinder. With the 200/2, when IS is activated it seriously "locks down" and there's no camera shake at all, down to about 1/10sec or so. While 1/10sec images might not be critically sharp, they are certainly more than usable.
Just a perfect lens all around. I can't think of a single negative word to say about it. The price is a bit steep, but honestly the lens backs up this price by setting a new standard in the Canon Super Tele line.
Big thumbs up to Canon for this one!!!