Not only is it ugly as all get-out, it looks like it's begging to spill hot coffee on a necktie.
Better idea: Give discounts to customer who bring their own mugs! I had a really nice coffee vending machine at work (it ground the coffee beans fresh and had an Espresso option), and it knocked a nickel off the price if it detected a mug inserted into the delivery hole. A little message would come on the price display that it detected a mug.
I had all sorts of travel mugs with lids and such. Still have them somewhere, but my get up and go got up and went. No commute.