Dead Guy Junior: Not referring to one of the characters, but Isthmus City president Hector Lopez was played by Pedro Armendariz, Jr., whose father, Pedro Armendariz, Sr., played Kerim Bey in From Russia with Love.
The Other Darrin: In a weird example of this trope, actor John Terry, who had played Felix Leiter in the previous film was replaced by David Hedison - who had played Leiter all the way back in Live and Let Die. It was felt that an actor who had previously played the role should be in this one, for a better emotional reaction to what happens to him.
Playboy: The Chinese ninja woman who also appears during the opening credit sequence is Diana Lee Hsu, May 1988 Centerfold. She is part of a tradition of having an actress in a Bond movie to model in Playboy, although she's the first to have been a Centerfold before making the movie. Look for her in Maurice Binder's photography-themed opening sequence.
Carey Lowell and Talisa Soto both declined to appear in Playboy.
Shout-Out: Bond is taken to Hemingway House to turn in his licence and his weapon. He comments that it's "a farewell to arms". Subtle...
Throw It In: Robert Davi wrote Sanchez' line about "Loyalty is more important to me than money."
Also the shot of Q throwing the rake-radio into the bushes was simply the actor putting it out of shot for the next scene, however the sight of Q abusing a gadget the way he always complains about Bond doing was too good to lose.
What Could Have Been: Had the film come out in October and been successful, the studio would probably have had faith enough in Dalton to greenlight a third Dalton Bond movie. Plans for one existed however, but 'legal issues' prevented it from ever being made.