How can I mirror my iPad display wirelessly?
This is possible using iOS 5 and an Apple TV using AirPlay.

This only works with iPhone 4S and iPad 2 and all video and sound are mirrored wirelessly to any TV that is connected via HDMI downstream from the Apple TV. You do need a wireless network for the two devices to communicate. 


  Just double-click the Home button, swipe all the way to the right, and
  select AirPlay Mirroring.


Reference: http://www.apple.com/iphone/features/airplay.html