But express was connect with some extra goodies on top. Surely this is an iteration upon express?

I guess I'm more concerned about the marketing of this framework as there's now two names for the same thing except one is newer than the other. As a dirty analogy - if jQuery started to support yields instead of function callbacks, do they change the name of the library?

Looking at the syntax of Koa, it's still express except it looks nicer because there's no callbacks. What was the reasoning for ditching the big name? It can't be just for that.