In Craig Hockenberry’s post marking the abrupt interruption of third party apps’ ability to access the Twitter API, he speaks to what he sees coming next:
One thing I’ve noticed is that everyone is going to great lengths to make something that replaces the clients we’ve known for years. That’s an excellent goal that eases a transition in the short-term, but ignores how a new open standard (ActivityPub) can be leveraged in new and different ways.
Federation exposes a lot of different data sources that you’d want to follow. Not all of these sources will be Mastodon instances: you may want to stay up-to-date with someone’s Micro.blog, or maybe another person’s Tumblr, or someone else’s photo feed. There are many apps and servers for you to choose from.
Twitter is clamping down their API. Federation is just starting up. Combine the idea of an ActivityPub client with Robin Sloan’s desire for a new format beyond the timeline and a whole new design space opens.