I have a configurable product and 3 simple products associated to it. As each simple product has a different description and a different colour swatch. When you click on the swatch the image and the sku change which is fine. However, how do you get the simple product decription and short description to change from whatever is in the configurable product?
There is an extension that is doing exactly this and much more. The other way is to extend getJsonConfig() of the configurable to have the values present in the frontend and then change the price-updating js function.