If you think about it, American has had the same paint job since the 70s haven't they? Do you think it will change anytime soon? Or will it always stay the same because its a classic? For example the New York Yankees, they'll change uniforms because its so classic.
If they change it, I think that it will be a minimal change, like maybe a new font for the titles or an additional logo or something like that. Most of their image is the metallic bird, and I think that it will stay that way for a good time.
I hope they dont. And if they do I hope they dont go through the convulsions Delta and British Airways have gone through (Delta's "Marc Chagal" scheme is atrocious and uninspired (thoguh at least if the painted all their planes like the "PowerPuff Girls" atleast they would set themselves apart from the rest of the boring white fuselages) and the cartoon tales of BA are so undignified(if they would stick with one, like "Chelsea Rose", that would be nice however).