The application in games I'm most excited about is commenters in FIFA career mode that don't have a limited set of prerecorded voice lines, and take your recent games, formation changes etc into account too, like real commentators would. The recent installments already do that to a small degree. Of course this would also easily open the doors to having multiple commentators/analysts to choose from, each with their individual "personalities". The technology for that is pretty much all already there right?

A game like Fallout/Elder Scrolls with AI generated NPCs and questlines would be so sick too if executed well.