Can you use your original Nintendo Wii with the new Wii U?

please only answer if you actually know. i saw some videos from E3, and the new system uses a touch pad controller, and a Wii system. I have the original Nintendo Wii. Do you need to buy a new Wii system, and the touch pad controller? or do you just need to buy the touch pad controller? and does anyone know how much it will cost?