I was able to watch the first episode of Fullmetal Alchemist: Brotherhood before everybody else decided that they wanted to watch it too and therefore grinding FUNimation's site to a near standstill.
The animation is spectacular. So far, the production values in this one just blow the first series out of the water. Even on par with the FMA movie, without the crappy CGI of course. I'm really liking this director and I guess that the reputation of FMA didn't hurt when it came to getting the money to fund this series. The art style has been made to be more in tune with the one from the manga. While I am a fan of the manga, they did try and adapt some of the same visual gags and it did seem rather odd seeing that animated.
The musical score shows a lot of promise. But I'm not a fan of the score of the original anime series, so take that for what you will.
The biggest complaint that I have in this anime only episode is that they revealed Ed's automail in a matter of minutes in a rather anti-climatic way. It's really disappointing. You also have to keep in mind that this episode is just fanservice. You're expected to know the characters beforehand and pretty much everything from the first series.
Overall, this show shows a lot promise from the production values side and having read the manga it gives me a lot of hope of what's to come.