Continuity mistake: After telling the joke about the Teenage Mutant Ninja Turtles, Marshall's hands change between shots, from holding his hand for a hi-five to his pockets to holding the Skittles. (00:08:32)
Other mistake: There is absolutely no reason for Ted to hang around underneath his apartment window while Jeanette is throwing stuff out of it. Any sane person would know that there is a very high chance of getting struck by the myriad of Ted's belongings that are wantonly chucked out onto the street. He's not trying to collect/catch anything because he is turned away from the building, and is not paying attention to the items that are being thrown out.
Chosen answer: In a flash forward scene in Season 8, it shows him with his first born: a daughter.
XIII