All Kidding Aside Meaning

(speech act, idiomatic) Used to attempt to make a serious point in a jocular conversation.

Example: 1983 April 25, Steve Wozniak, letter to the editor, Infoworld,
  All kidding aside, I doubt we'll ever bomb Japan as long as [the Japanese] make Epson printers.
2002, Anne McCaffrey, The Mark of Merlin,
  "All kidding aside, Carlysle . . ."
  "Carla," I corrected him automatically.
  "I'm too used to thinking of you as 'Carlysle' and male to change both at once . . . All kidding aside, it'd be better for you not to stay on here any longer than the storm."
2009 February 19, Joe Biden, speech, The Good of the Nation,
  Max, just remember, when we call, I call, just say "Yes, Joe," okay? (Laughter.) All kidding aside, thanks for your great help in this, Max.