As Atrios points out...it was one year ago that Stephen Colbert did this.
How has the White House responded? Well, um...they hired political firebrand Rich Little (if you do not know who he is, he was AWESOME in the 80s- with his harmless criticisms of President Reagan and Johnny Carson). Apparently, Yakov Smirnoff couldn't make it.
Just to make sure that nothing goes crazy, the President has made sure that any criticisms of his presidency are kept on the DL. Good for him.