The first thing Envy says upon meeting Ed is "Arara", an expression of surprise and interest. It is often uttered by Conan Edogawa when he's playing dumb.
Nana Mizuki played Wrath in 03 who was a bad tempered black haired homunculus who seemingly acquired Ed's limbs through the gate. Come Brotherhood she was cast as Lan Fan who is... a bad tempered black haired girl who sacrifices her arm in emulation of Ed.
Adored by the Network: Brotherhood has essentially replaced the original anime, which has not aired ever since Adult Swim started airing Brotherhood (and which AS no longer has the rights to). It stayed when [adult swim] Action was replaced by the revival of Toonami, and so far, as of January 2014, Brotherhood (along with the long-running Bleach) has the distinction of being the only show on Toonami that has managed to stay on the lineup ever since the block was revived.
The Cameo: Aaron Dismuke, English voice of young/teen Al in the 2003 series and The Conqueror of Shamballa, appears in a brief role as Young Hohenheim as he couldn't reprise the voice of Al (due to his voice obviously breaking).
Crossdressing Voices: Al is voiced by a woman in Brotherhood; notable since he was actually played by a young boy the the first time around. Selim Bradley was also played by a woman, and Envy retains his/their female voice actor from the first anime.
Fan Nickname: Due to his lack of name, fans had to be rather creative with giving the gold-toothed doctor a name. Some variations include "Bastard Doctor with the Gold Tooth," "That Bastard in White," "Gold-Tooth Bastard", or "Bastard Doctor Who Slit Riza's Throat."
Keep Circulating the Tapes: Funimation lost the license to Brotherhood on March 31, 2016. Hope you didn't put off buying it before then. It's still available for streaming on Crunchyroll, though. And as of January 1st, 2018, the full Brotherhood series is on Netflix.
Aniplex USA is now making two new Blu-Ray sets for the series that include both the show and the OVA, though as expected of their releases, you can expect to spend a lot of money on them. Used copies of the out of print Funimation sets remain cheaper, at least, though prices may vary.
No Dub for You: The Netflix's Latin American Spanish feed used in the series removes the very controversial Spanish dub, partly due of its quality and partly because it was censored to boot, so the only language versions used there are the original Japanese and the English dub.note Officially, the reason for the lack of the Spanish dubs in Netflix was because Aniplex doesn't have the rights for using the Latin American dubs, since they were done by request of Sony Entertaiment Television in Venezuela. Since Aniplex rarely dubs anything outside English, the series end up without one. The live-action film did had one because the dub was done on request for Netflix in Mexico.
While a majority of the original English dub cast reprise their roles from the 2003 series, Alphonse Elric, Scar, and Hohenheim had to be recast. Aaron Dismuke couldn't reprise Al's role thanks to hitting puberty and was replaced by Maxey Whitehead. Scar was originally played by Dameon Clarke, who was unavailable and was thus replaced by J. Michael Tatum. Scott McNeil likewise could not return to reprise his role as Hohenheim and got replaced by John Swasey.
Marcoh and Breda also received new voice actors in Brotherhood. Marcoh was voiced by Brice Armstrong in '03 and Jerry Russell in Brotherhood, while Jeremy Inman replaced Josh Berry for Breda.
Brotherhood replaced a good deal of the Japanese voice actors from the first anime, with the exceptions of the Elric brothers of course. Two who returned ended up playing different characters. In contrast, the English dub retained nearly all of the original voice actors; the changes basically amount to Al, Scar, Hohenheim, Marcoh, and Breda.
Brotherhood is not the only instance of Gundam and Fullmetal Alchemist sharing several voice actors, the original anime also featured several voice actors from Mobile Suit Gundam SEED. So it's probably a safe bet that if there is a FMA anime, then they will most likely follow after a Gundam series, and have several voice actors in both.
Screwed by the Network: Important bits of the plot have been cut for time from the [adult swim] broadcast, particularly regarding Mustang and his group after he makes his move just before the Promised Day.
Talking to Himself: In the original Japanese version of Brotherhood, Alphonse and the miniature panda Shao May are both voiced by Rie Kugimiya. This was averted in the dub.
What Could Have Been: Lan Fan's actress wasn't available for the final episode of Brotherhood, meaning we miss the end of her character development from the manga.
Approval of God: Due to a mix of not wanting to tell the same story twice and the risk of overtaking the manga, Arakawa encouraged and approved of the changes made to the story in the 2003 anime, even designing several characters for it. Heck, she liked some of the Canon Foreigners so much that she added them to the manga!
Cross-Dressing Voices: Ed and Al are voiced by women in Japanese, but not in English. Envy, however, is voiced by a woman in both versions. It contributes to his/her/its creepiness quite effectively. Wrath also has a female voice actor in both Japanese and English.
Cut Song: "Melissa" (the first opening song) and "Undo" (the third) were unused in the North American airings of the series; "Ready Steady Go" (the second opening) replaced them instead, with the opening finally changing once "Rewrite" (the fourth) comes along in the final stretch of the series.
Vic Mignogna on many occasions was not actually shown the entire script, and his lines were all recorded in chronological order. As a result, his surprise at what was on the other side of the Gate of Truth and what originally happened after the Shou Tucker incident, and Vic's sadness in the last few episodes, were legitimate reactions.
When Al was hit with a teacup in one episode, a teacup was tossed at Aaron Dismuke's face.
Fan Nickname: The series itself is sometimes referred to as Feelmetal Alchemist, thanks in no small part to its very emotionally driven tone.
God Never Said That: Quite a few members of the manga/Brotherhood fandom seem to think that the changes in the anime were made with no input from Hiromu Arakawa and that she disapproved—if not disowned—the whole thing. In reality, Arakawa not only greatly approved of the changes, she actively encouraged them (mostly because she knew the anime would overtake the manga and the anime wouldn't have enough time to keep up).
The original French dub which aired on Canal+ is the one fans tend to prefer, as they feel the abundance of coloquialisms and curse words made Ed's dialogue (among others) feel more natural and lively. It's become unfindable legally ever since the DVDs came out (with a lot of lines redubbed to make them tamer), but some people still managed to dig it up and make it available again on torrent sites.
Quasi-example: the Licensed Game, Fullmetal Alchemist and the Broken Angel, was released in the US just two and a half months after the anime's [adult swim] premiere, but was localized before the dubbing of the anime began; thus, all of the US voice actors were cast for and recorded the game before starting on the first episode.
Broken Angel also played this straight with Alex Louis Armstrong, as the game featured him a full month before the episode with his first appearance in the anime aired on U.S. television.
Overtook the Manga: A somewhat unusual case, in which the creator of the manga specifically asked the people making the anime to do this, since the manga was nowhere near being completed at the time the anime came out.
No Dub for You: Averted by Netflix, which produced dubs in Latin Spanish, European Spanish, French, German, Italian, Brazilian Portuguese, and Korean. This is especially relevant, as Netflix rarely dubs non-Hollywood live-action works, and this film is a big aversion of that policy. Interestingly enough for Latin American viewers, unlike the anime, which was dubbed in Venezuela, this one was dubbed in Mexico, albeit with a glaring exception (see below).
Role Reprise: A cross-country version of this trope: Jhonny Torres, the Venezuelan voice actor who voiced Alphonse in the anime dubbed in that country, reprises his role in the film, despite being dubbed in Mexico. This is because Torres moved to Mexico due to the social and economic crisis in his homeland (as of 2018).
The European Spanish, French, and Brazilian Portuguese dubs also kept most of the anime cast. Averted in Italian, as the dub moved from Milan (anime) to Rome (the movie).
Acting for Two: Romi Park and Rie Kugimiya, Edward and Alphonse's voice actresses in the Japanese version, voiced two of Major Armstrong's family members who are his mother and his younger sister Catherine for one episode in both anime series (episodes 37 and 45 respectfully). Kugimiya also voiced Xiao-Mei in Brotherhood as well. Averted in the English dub of both series, however, where the five are portrayed by different voice actors.
The English dub of both series has Caitlin Glass voicing both Winry and her mother Sara, and Colleen Clinkenbeard voicing both Rose Thomas and Riza Hawkeye. Averted in the Japanese version, however, where the four are portrayed by different voice actresses.
Hoho and Hohopapa for Hohenheim, Scarbro for Scar's brother, Sexyhobo/Gar for Scar (no, really!), Shinri-kun or Truth-kun for the guardian of the Doors of Truth, Greedling or GreedLin for Greed once he takes over Lin/Ling's body (Ed does use "Greedling" in Episode 45 of Brotherhood).
Also Bob the Blob/Proto-Father for Father's original form, Mr. Monopoly, Colonel Clean (a.k.a. Sparkleman), Palm Tree, Shota McShadowrape, Ninaxander, the Pimp Suit, Fetus!Envy, and Godfather.