Jennifer - Hi - I'm the executive editor of the American Heritage Dictionary. I've been in contact with Mary at Immigration Impact since Friday. The lack of an offensive label at "anchor baby" was an error which I acknowledge and apologize for. The offensive label has since been added in our online dictionary and will be dealt with in print in upcoming printings. We are still working on revising the definition itself, too.
I signed your online petition, but please know that we're already working on it. Thank you for your passion in this regard.
Please check out immigration impact's website -- they have full details about the change, etc. in their update.