According to ESRB, this game contains: Blood, Fantasy Violence, Mild Language, Suggestive Themes
Parents should be fairly comfortable with their teens playing this game. Yes, it contains some mature themes and plenty of violence, but it's all presented in a fairly innocuous fantasy context, more than safe for anyone who's seen Lord of the Rings, for example.
Fans of the series have no reason not to pick this one up. It's all as good as it ever was.
Deaf and hard of hearing gamers won't have any trouble at all. Everything of importance is subtitled, and there aren't any important audio cues.