Pluto is a ball of ice and rock. It doesn't have any feelings. It neither knows nor cares that a bunch of Earthlings came up with a category called "planets" to include the larger and more important objects orbiting the sun. Nothing that you know about Pluto has changed except for which side of one arbitrary dividing line it falls on. And if all you know about Pluto is "it's a planet," you may want to think a bit about why you feel qualified to hold an opinion on this issue.
It's true that simply cropping out Pluto leaves the traditional mnemonic as "My Very Excellent Mother Just Served Us Nine." However, this is neither an original observation nor an appropriate subject for existential angst. I'm sure that somehow, someday, the collective creativity of the English-speaking world will be able to come up with a new mnemonic device.