And stick some narration over the top.
If something like what you say got implemented, I'd narrate any audio for free!
If you've ever played Bastion, you would know exactly what I mean and how powerful story driven content (in Bastion's case, flexible and intelligent AI narrative) can be applied to a simple hack'n'slash and make it interesting as the player progresses, and changes their mind. AoC already sell's itself in the story department, so it's a win all round as I see it! Besides, in one of the interviews they mentioned voice actors only ever utilisied one or two hours of their paid-for four (or something along those lines). This would be a great use besides filling in old content.
Some one get James Earl Jones on the phone!
Ahh, we can dream.