And am I the only one who organizes the episodes in story arcs? Like, episodes 1-3 are an introduction to Ed and Al and would be ideal for the first disc, while 4-6 continue the flashbacks, and 7-9 start the angst and end the flashback arc quite neatly. Episodes 10-13 are mostly fun fillers and end the first season, while episodes 14-16 start the second season with the introduction of Scar and the Ishbal storyline.
That's the main reason I'd personally prefer the 3/4 eps per DVD, despite the cost, and why I don't quite agree with how the Japanese DVDs are organized sometimes. Also taking into account the packaging (assuming the American DVDs will use the same covers as the Japanese), it'll make more sense to use the 3/4 episode count (though we might run out of covers before long).
Please don't kill me.
Edit: *ahem* In an attempt to salvage this entry, you can find a video of a panel from AnimeFest here. Includes the VA's for Ed and (I heard this somewhere) Havoc. Not that much info, but it's rather amusing.