Takuhi said:They sounded pretty good! Pretty professional for the main parts, kind of generic for the soldiers on the field (as you'd expect). I asked if there were any known voice actors and they said they were all recorded locally in Texas, so apparently not.
Also, they refused to comment on whether or not a voice actor was hired for Samus. Which surely means yes, right?
In an interview with AMN during E3 '06 they said that Samus would be a silent protagonist again. They could've changed it, but I hope not. I like my silent protagonists.