Sean Hannity is already on this, and I can't imagine the others are far behind. "Obama wants to make our children speak Spanish! This must be stopped!" They'll find a way to make this rather benign observation seem threatening - probably by forcing it into the right-wing storyline that Obama is foreign, elitist, and "embarrassed" by Americans.
Of course, his comment is true; while Americans benefit from speaking the lingua franca, learning another language is a rewarding endeavor. It's a wonderful way to gain appreciation of other cultures, to say nothing of the benefit of being able to communicate with whole new groups of people.
When was the last time President Bush asked anything of Americans? Obama's asking us to embrace nuance in our politics, to learn new languages, and to perform community service. Let the wingnuts attack all they want. This is what leadership looks like.