I frankly think it's more important to help kids understand that science is an openly skeptical, ongoing form of inquiry and learning, than it is to make it possible to keep the old mnemonic ("my very educated mother just sent us nine pizzas"). Which, of course, is what most of these stories have focused on: how difficult it will be for kids to change what they've learned in school. Frankly, having to have a mnemonic at all suggests that what most kids learned about planets was how to spit back a factoid on a test (eg. "name the planets in order"), rather than what constitutes the classification "planet," let alone why it might matter.
I think it would be GREAT for kids all over the world to learn that what teachers have taught them may no longer be true (if it even was at the time), and that they should always remain critically engaged in the search for truth.