Wiki subverted the paper paradigm, and became a unique form of writing for the digital age. It produced Wikipedia, the One Impossible Thing the web has produced.
But federation is just one part of the system. Federated wiki addresses a potentially more serious issue. We live in a digital world, but we continue to think Paper Thoughts.
We won't deal with the data features of fedwiki in our fourteen day experiment, but federated wiki started its life as an investigation of what happens when you treat Data as a First-Class Citizen.