More good news: WIC will begin using the WHO Growth Charts this year, beginning October 1st.
The CDC and the AAP have both endorsed the WHO charts, which use the breastfed baby as the norm for infant growth and are to be used with all children, regardless of feeding method. They've been in use in the U.K. (and other countries) for a few years.
These charts will more accurately reflect both breastfed and formula fed babies' growth, reducing the chances that breastfed babies will be seen "falling off the curve," and allowing pediatricians (and in this case WIC) to pick up on increased risk of overweight in formula fed babies as well.
For more information about the charts and how to use them, see this CDC training module.
Just another thing to be thankful for this year!