Okay, custom domains are discoverable and have all endpoints in place. Now just need to let everyone choose their handle. This will go in a new "Federation" section on the blog settings page -- a page that's starting to get a little long I think, so I'll have to redesign it a bit in the near future.
Something I'm looking forward to: non-technical users seeing this new setting on their blog and asking me what it means. I have no doubt it'll be confusing to the uninitiated, so it'll be nice to hear everyone's questions, and figure out how to explain federation in a way that makes sense to them.
Based on that, I can tweak the UI so more people understand what's going on right away. Enough of that, and more people will be able to join the fediverse without the whole learning curve.
@tomskee The feature isn't completely finished yet, but right now Write.as blog posts can be federated, that is, followed from federated platforms like Mastodon. For example, here's mine: @matt@write.as -- you can follow it here, get my posts, and favorite / boost them on your Masto account.
So the stats you're seeing on Write.as are how many blog followers you have in the "fediverse" / on Mastodon and similar platforms.