Throughout the following, just-released trailer for the English version of Bravely Default, it's stated that players can choose between either English or Japanese audio.
I hate to say it, but after watching said trailer (which can be seen below), I'm definitely going with the latter, as the English voice acting seems ... well, let's just say it's not the best I've ever heard.
Who cares, though, when everything else sounds and looks so wonderful? I especially love the character designs and the backdrop art. Oh, and Revo's dramatic soundtrack, of course.
By the way, according to a recent Nintendo UK tweet, Bravely Default's still due for a 2013 release throughout Europe. Lucky bastards.