I doubt translation will be much of a problem. I'm going with the theory that NIS would act as a publisher for a US release. Believe it or not, there is a VERY good translation (done via an english language patch) done by Witch Hunt which was approved of by 07th Expansion. If Umineko gets released, there would probably be some collaboration with Witch Hunt/07th Expansion making that process run smoothly.
As for if the game will be dubbed or subbed if it gets a release, I cannot be certain. Depends on cost of dubbing. This brings up the question of what such a game could be compared to in terms of hours of dialogue for games of other genres (long length RPG for example).
One can only dream. A toast to hoping that it comes true one day, and maybe a state side release of the DS version of Higurashi No Naku Koro Ni.