The Wii U GamePad screen will lag behind your TV

Here's another reason for hardcore gamers to eschew the Wii U: Rayman Legends developer Michel Ancel gave Nintendo Power (RIP) details on the lag between the Wii U GamePad and the image on the TV. Here's the bad news: there is definitely lag. Here's the good news: it should only be 1x60th of a second, or, one frame behind what's happening on the TV. Since the Wii U will support two gamers playing simultaneously one on the Gamepad screen and one on the TV, this could be a significant disadvantage to somebody playing on the GamePad. .
Most media outlets have spun the slight lag as something that most people won't be able to notice.

Ubergizmo , The Wii U GamePad screen will lag behind your TV

See also:
wareground, The Wii U GamePad screen will lag behind your TV