What would Kim have to gain? If she wins another few World titles and defends her title in Sochi she would be virtually the unanimous greatest ever. She would be the first women to defend an Olympic title since Witt in the 80s as well. In terms of finances and fame she has nothing more to gain I suppose, but from a historical perspective she has alot.
I see more chance of Czisny hanging on for Sochi at 26 than Ando. Once the Japanese get a 2nd up and comer to go with Murakami I predict the Japanese would be ready to dump Ando from the World team, as long as Asada stays reasonably strong. I doubt she will let it get to that point though and will retire after this season, especialy if she wins a bronze or silver at Worlds, so will wisely get out before she gets dropped from the Japanese World and Olympic teams and make lots of money in shows and other ventures in Asia as a former World Champion and very beautiful/personible young women. Skating wise is pretty much hitting her peak (or as much as she can hit at this point in her career, her real peak was 2007) and the soft post Olympic year is giving her one last chance for some success and I am sure she knows this. Her jumps wont get any better at this point, and she already doesnt do the triple-triples anymore, she is maxing out what she can now with backloaded and smart COP jump layout, good quality jumps, and inflated rep PCS. Her artistry, spins, and spirals will never be more than mediocre at this point. There is really nowhere to go for her after this season, especialy as the up and comers emerge, and the other star vets begin skating more regularly/consistently again. Czisny though seems to be a late bloomer so could conceivably hang on for Sochi. I am sure she wants to skate at an Olympics, regardless of her chances for a medal. Unlike Ando there is still lots of room to grow in her skating and she has a variety of positive assets that could keep her in consideration in the coming years.