The programme of the next Summer School will be available late January. When the programme is published and registration opens, a message will be sent to everyone on the mailing list (persons who have registered and participants in former Summer Schools).
Although the programme varies from year to year, several workshops (high demand) are repeated yearly, many others every second or third year. This, of course, depends on the availability of instructors.
A look at the earlier Summer School programmes will give you a general idea.