That probably won't remain the case, though. After the coming memetic takeover we are likely to have an engineered future - and then it will be memes all the way down.

The memetic takeover you describe would just consist of intelligences running on computer-like substrates instead of organic substrates. That isn't morally relevant to me, I don't care if the creatures of the future are made of carbon or silicon. I care about what sort of minds they have, what they value and believe in.

I'm not sure referring to an intelligent creature that is made of computing code instead of carbon as a "meme" is true to the common definitions of the term. I always thought of memes as contagious ideas and concepts, not as a term to describe an entire intellect.

After the memetic takeover there would still be intelligent creatures, they'd just run on a different substrate. Many of them could possibly be brain-like in design or have human-like values. They would continue to exchange memes with each other just as they did before, and those memes would spread or die depending on their usefulness to the intelligent creatures. Just like they do now.