Good news! I just found out that we should be receiving another batch of the EK-TM4C123G Tiva C Launchpads over the next two days. Orders are shipped on a first-come, first-serve basis. This means if you place your order for the Tiva C now, you should get it in time for class.
Please note this applies only to the Tiva C Launchpad, not the Stellaris Launchpad (EK-LM4F120XL).
Hope this helps!