You will now be able to assign products to categories in bulk, using their SKUs. In the 'Products' view, click on the category you would like to merchandise, and then click 'Assign Products.' As can be seen in the screen shot below, a window will pop up, into which you can paste up to 200 SKUs at a time. These will then be added to the category in bulk. SKUs must be separated with a comma and no spaces, e.g SKU1,SKU2,SKU3 etc.