Hmm...this is tough.
I don't think Kane has very much talent, so I don't know how long his popularity will last.
I'm afraid Ghesquière might be popular for only this moment. These past two years have been all about him, and this may just be his fifteen minutes. (Though he is really talented.)
Karl will be an icon for his personality alone. Valentino will be forgotten because other than a very specific kind of 40's elegance, he didn't really bring anything to the table. Galliano will probably be remembered in fashion history books as an example of the decadence of our time. Vivienne Westwood is an important character, too. Tom Ford and Hedi Slimane are also big figures.
Elbaz, Pilati, and Theyskens most likely won't be 'icons' because their work isn't groundbreaking, it's just beautiful and timely. I'm undecided on Miuccia, though.
On the editorial side, I think Anna Wintour will definitely be an icon because of her personality. Roitfeld might be remembered for her style, but that's it. I can't think of any revolutionary models, though. Maybe Gemma Ward or Lily Cole or whoever the first 'alien' was.