I understand it's due to connect being bought by sencha. The FAQ states it's more like connect, with some express goodies moved to the middleware level.
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.