Fan Nickname: Tony's Abusive Boyfriend, for the armour in the arc in which the Iron Man armour became sentient.
Name's the Same: The current Whiplash shares his name and ethnicity with the original Crimson Dynamo, Anton Vanko, and his codename with Mark Scarlotti.
Technology Marches On: A frequent victim. One early story has him use a counting device built into his armor. That was quickly made obsolete by the real life invention of the pocket calculator. Nowadays he uses an AI for such things. Another major example of early mentions of technology that would now be out of date, is that his suit was powered by transistors.
Divorced Installment: When the show was cancelled after two seasons, the tie-in action figure line was axed before the fifth wave could be released. The figures were repainted, given new head sculpts, and then released as part of the toy lines for Spider-Man: The Animated Series and X-Men.
Edited for Syndication: A rather unusual case. When the show was on Netflix for a while, the show was, for the first time since its' original broadcast, presented with its' original Marvel Action Hour branding (and the Fantastic Four episodes were included, despite nothing in Netflix's listings indicating that) and Stan Lee intros! (The only thing changed in this case was removed the outdated Marvel and Genesis and/or Saban logos in favor of the current Marvel Animation logo.) However, season 2 was rather strange since the season 1 Marvel Action Hour intros were edited together with the season 2 intros, apparently to remove any trace of the Marvel Action Universe branding they used for that season (possibly because for said season, IM and FF were joined by another New World show, Biker Mice from Mars, which Disney doesn't own the rights to); it was very obvious as the voiceover suddenly switched from Jim Cummings to Tom Kane.
Dorian Harewood took over for James Avery as War Machine, Whirlwind, and Whiplash early into Season 1. Strangely, James Avery returned to voice War Machine in Spider-Man: The Animated Series, despite Harewood having already taken over the role by that point.
Harewood, Robert Hays (Iron Man), John Reilly (Hawkeye), Jim Cummings (M.O.D.O.K.) and Neil Ross (Fin Fang Foom) were the only cast members to return for Season 2. Virtually everyone else was replaced.
Century also suffered from this... twice! His original voice actor James Warwick was among those let go in-between seasons. In "The Beast Within," Jim Cummings takes over voicing the character. But in "The Hands of the Mandarin" two-parter, fellow series regular Tom Kane had the role instead. (This was most likely because H.O.M.E.R. didn't appear in Part 2 and production wanted Kane to have something to do.)
Troubled Production: The show was a mess behind the scenes, with Marvel viewing it as an afterthought whose sole purpose was to sell toys. The second season had no producer until three months into production, which resulted in 24-hour work days with no weekends off. The staff also had little say in things about plots and character designs, which were largely dictated by Marvel and Toy Biz.