Anyway, from the L'arc En Ciel's profile page on the Otakon website:
“FULLMETAL ALCHEMIST” will begin airing on Cartoon Network in November 2004 with the L’Arc~en~Ciel song as the theme song.
So does this imply that Ready Steady Go will be the OP for all 51 episodes on CN? I bet that's the case because:
1. It's too expensive to pay royalties to four singers (or eight if you count the ED)
2. L'Arc en Ciel's the only singers from FMA that have an album released in America
3. The L'Arc En Ciel opening was the one posted at Funimation's site when it first opened
I don't mind, Ready Steady Go is my favorite OP and unlike #3 and #4, it's spoiler free. Still, the multiple OP's were great since not everyone liked Ready Steady Go.
I'm thinking there may be only one ED too, though this might be tricky since the first two were sewn into the last few seconds of the show. Y'know, I kinda miss that effect, too bad they stopped doing it w/ #3 so they could add more commercials. :P