Mario's new voice actor is... you. When you see the movie, Mario's voice is yours. You don't remember recording any lines. Nobody does. They all hear their own voice as Mario's.
When the movie ends and they walk out of the theater, everybody in the audience now has the voice of Charles Martinet. A surprise cameo indeed.
The very tiny home of CaptainSpam and all the various goings on at Exclaim Industries (which is just CaptainSpam).