From a locavore standpoint, she could help promote the benefits to health, local growers, environment etc about what is going on the plates for state dinners.
When she talks, people are really listening. I admit that I am very curious about her as a person and what she thinks. Side note: for the first time, we have a First Lady that I can totally relate to.
Another thought. I'd love to see a website that included menus from all big dinners hosted by the White House. Wouldn't that be interesting?