More goodness from the engineers down the hill from me at UC Berkeley. The quad can see and catch ping pong balls! Life is good if you've got a Vicon motion caption system and an Ascending Technologies quad (ie, a big research budget).
From IEEE Spectrum:
This technique is called LBMPC (that's Learning Based Model Predictive Control), and you can see it in action when the quadrotor needs to move sideways to catch the ball, as it figures in the fact that it's going to drift a little bit after it cancels out its lateral movement. Clever.