Doraemon/Trivia

Author Existence Failure: Fujiko F. Fujio died in 1996. Later works were done by Fujiko Studio, a group of his apprentices.
Missing Episode: The 1973 series. The Fujiko duo hated the show and pretty much buried it - apparently it was conveniently "destroyed in a fire" shortly after it was canceled. Some episodes survive in certain people's hands but otherwise the show just plain doesn't exist.
Name's the Same: Both Nobita's father and his future son are both named Nobisuke, fitting with the running theme of "Nobi" being the first two syllables of their names. It hasn't been addressed, so it's uncertain whether future-Nobisuke was named after his grandfather or if it was just an accident.
No Export for You: Despite being a popular and classic anime series (if not the classic kids anime) that has Outlived Its Creator, the series has never licensed for North American audiences, despite still going for 30 years.
Outlived Its Creator: Fujiko Fujio is a pen-name shared by two artists. One of them is dead. His apprentices have continued writing the story and its spin-offs in his stead.
Role Reprisal: In the 2005 anime.
Serial Numbers Filed Off: Due to the popularity of Doraemon in Malaysia, there are unauthorized prints of the manga. These typically goes by the title of Labu-Labi and looks cheaply printed. Official prints bear the Doraemon name and tend to be of reasonably better quality, but unfortunately costs much more.
What Could Have Been: The American fans wouldn't be surprised that Ted Turner used to have the rights to the anime in 1985 and was suppose to air it on SuperStation WTBS (Now TBS, very funny) with 50 episodes. However, they couldn't get a TV deal for it and let the license expired. This could've been Doraemon's first appearance in the US, and almost 30 years earlier too.
The Wiki Rule: Doraemon Wiki