Inventory Quantity on Configurable Products

It would be great to have in the Product Essentials box, the inventory count of a selected child product in the configurable product be displayed. This way, customer complaints of trying to unsuccessfully add products with too high a quantity can be done with.

Two implementation methods I could think of would be: either have it be loaded as a javascript variable to be updated when the child product is selected as with the product images, or have it call via AJAX an updated count even if the page has been loaded for a long time.