I already own the 100mm L macro, thats the only reason I mentioned it =)
From Jeffrey's great post it generally is seeming like I might be more happy with the IS II, but its made me really think about have exactly I plan to use the lens.
Sometimes I like to fool around with shots in my apartment and I doubt I will have enough space to shoot at 200mm inside here. Would probably be better with the IS II when I am outside though.
Guess it also depends on your goals... the two example photos I linked dont have the subjects entire body's depth super sharp - they both would probably have popped more on the 200. But I like those shots anyway, they are interesting beyond just the subject.
Might just have to get both haha