We probably want to indicate that this is a fork of the Microsoft.Owin stack for those interested in receiving continued support, maintained by the OSS community. That would provide context and a message of continuity. We probably should also provide a promise not to break the world. I'm sure some may be aware of our obsoleting IAppBuilder and wonder if we would do the same here. We can probably push some evolutions as we evolve OWIN, but we should make an effort not to drastically break anyone.
Other than that, I'm excited you picked this up, Damien. Thank you!