The 6.2" screen in the centre of the Wii U controller is likely to use the same resistive technology that features in the DS and 3DS consoles, rather than the more advanced capacitive system used in modern smart phones and Apple's iDevices.
Hardware images released by Nintendo show a stylus being used on the touch screen, indicating resistive technology at work as capacitive screens require special styluses to function.
On a technical level, resistive and capacitive screens obviously share an overarching trait — you touch them, they respond — but both are suited to different tasks. Capacitive screens work better with fingers and can track multiple inputs, whereas resistive screens are more suited to drawing and writing as they work with styluses.
Nintendo's Wii U E3 2011 video also backs this up, as only single inputs are shown and a drawing of Link is clearly demonstrated.
If the Wii U controller does indeed feature DS-standard touch sensitivity, how would you feel? Let us know in the comments.