Mark your calendars, guys! :)
We'll do our absolute best to release the game with its voice acting included. If for any reason we're unable to hit the deadline, we'll release on the promised date anyway, and then patch the voices in as soon as we're able.
We're aware that the timescale is quite tight, but we're pretty confident now about the release date - we know what's left to do, we know we can do it, and we definitely want you to be able to enjoy our tale before Christmas. :)