Ability to change the sort order of variations on a product using drag and drop functionality

It would be great to have the ability to change the sort order of variations in a product using a drag and drop feature. For example if we have 10 colour T-Shirts in the same product and in the black colour we only have Small Medium Large, and we wanted to add extra large. It would be great to add this and then drag this up in order with the other variations. It would make life a lot easier when updating inventory.