The level of intelligent "prosody" here -- the rhythm and intonation, the pauses and personality -- I wasn't expecting anything like this so soon. This is truly remarkable. It understands both the text and the prompt for how the speaker should sound.
Like, we're getting much closer to the point where nobody except celebrities are going to record audiobooks. Everyone's just going to pick whatever voice they're in the mood for.
Some fun ones I just came up with:
> Imposing villain with an upper class British accent, speaking threateningly and with menace.
> Helpful customer support assistant with a Southern drawl who's very enthusiastic.
> Woman with a Boston accent who talks incredibly slowly and sounds like she's about to fall asleep at any minute.