What's after the “Age of Em”?

According Robin Hanson, there's a strong possibility that the next exponential mode will be dominated by robots emulating human personalities. This includes the following speculation:

This era may only last for a year or two, after which something even stranger may follow.

My guess is that the age after that will resemble “Slow Tuesday Night” by R. A. Lafferty and the one after that will be the long-awaited “AI Foom.”

“That may be an end or a beginning, but from here it is out of sight.”—J. D. Bernal in The World, The Flesh, and The Devil