Mmm, yes... apparently "Ready Steady Go" is going to be the only opening used in the American-broadcasted version of FMA. I'm hoping when it comes out on DVD they'll use all the openings.
Did you get a translation of the lyrics? There's a line about "if a map is unreliable, just burn it", that I find amusing. www.animelyrics.com is pretty good though their translations can be spotty.
Apparently in about two weeks, the open/close is changing yet again, so there'll be a fourth pair for us to listen to.... oddly, I don't like "Undo" nearly as much, but there's a line I love - "ano egao wo mo ichido", which means "I want to see that smile again".
Openings and such rarely have anything to do with the anime, but in this case, they work really well!
Oh, yeah, and how on earth can you rhyme "can't hold me back" with "give me good luck"?