Afaik, some examples of creative agencies who have used Meteor to build sites for their clients:
- McMillan http://www.mcmillanagency.com/
- Q42 http://www.q42.nl/
Some production apps include:
The way it would transform it is if you could find a way to make it more like a web-app. A good way to think about pushing your site to keep fresh, but isn't necessarily a needed direction to go in.