Originally, the character of Remington Steele was supposed to be a figurehead, comic relief to be used in support of Stephanie Zimbalist. Brosnan became so popular, that his part became more significant.
Robert Butler originally pitched the show to MTM as detective Laura Holt running a detective agency belonging to a male superior, whom she invented for business purposes. MTM put Butler in contact with Michael Gleason, who suggested the chaos that would ensue if the invented superior turned up one day, and the character of Remington Steele was created.
During the run of the series, Pierce Brosnan was not only touted as the next James Bond, but he was also mentioned in published reports as being considered to star in a theatrical version of The Saint (1962). This project never materialized.
Director Chris Columbus is a big James Bond fan, and he was crushed when Pierce Brosnan didn't get cast when he was offered the part during the making of this show, but they wouldn't release him from his contract. Columbus thought Brosnan a phenomenal actor. When they worked together on Mrs. Doubtfire (1993), Columbus told Brosnan he'd make a great James Bond, but Brosnan thought that ship had sailed. In 1995, MGM called Columbus telling him they're looking for the next James Bond, and Brosnan was one of the choices, so Columbus recommended him; his little contribution to the James Bond saga.
The trivia items below may give away important plot points.
Recurring character "Daniel Chalmers" was a con man, who mentored a man he called "Harry" in the art of the con. 'Harry' eventually became Remington Steele. In the final episode, Chalmers confessed to Steele thay they were father and son. Tragically, Chalmers died of heart failure before he could answer Steele's eternal question, "I've always wondered, Daniel, what's my real name?"
In season one, episode fourteen, "Hearts of Steele", Steele attempts to solve a case by referencing The Thomas Crown Affair (1968) starring Steve McQueen. Pierce Brosnan starred in the 1999 remake of the movie.