Some of the fleet will probably go to the Air National Guard, particularly the Texas ANG, A few will end up in the hands of collectors.
If there's a reasonable use to be found for them in the next decade or two, we'll probably have a chance to see them get put to it.
There was an apparently serious proposal some time ago to use A-10s as hurricane chasers. However, that mission is already well-handled by C-130s, and the A-10 doesn't really have the payload capacity for the sensors and technicians needed.