4/3:

"The Daily Show"'s John Oliver did this send-up of the Michelle Obama-Queen touch on Thursday night's show.

4/2:
UPDATE:

Buckingham Palace has issued a response to the controversy, denying that there are rules about touching the Queen. From the Associated Press:

A Buckingham Palace spokesman who asked not to be identified because of palace policy said he could not remember the last time the queen had displayed such public affection with a first lady...