One fan wanted to know why the Japanese voice actor for Snake (Akio Otsuka) has not changed, while the English actor (David Hayter) has. The host of the podcast, Sean Eyestone, answered:
This time, the English voice is really driving the animation, is driving the character. In past Metal Gears, everything was done by hand: the animation was done by hand, both the English and the Japanese were dubbed in.
This time, the facial performance that is being done by the English voice actor is what is driving the animation, what is driving the character. And actually, Otsuka-san, who is the Japanese voice, will be dubbing into that. So his facial expressions will not be in the game, so its just his voice. Its like what hes done up to this point. So thats more or less the reason why this casting decision was made.
I know some people may have reservations, whenever things change, people are always a little nervous. But I think if you just wait and see how things turn out, I think youll be very happy with the performance. I think its really cool and we cant wait to show you more.
http://metalgearsolid.nl/?p=8231