Threads website is sort of live? Clean, but somewhat bare. One positive thing is the domain name right after the username. Looks like the Fediverse connection isn't just talk.
Looks like threads is off again (I almost said down, but it isn't Twitter) so I can't link directly to the post/thread. But I'd say this is a good commitment to being federated.
Just to be clear, this means that you'll be able to interact with folks on the Threads network, just like you can with any other instance. It doesn't mean you'll be able to use your favorite Mastodon client to log in to a Threads account. I very much doubt they're ever going to have an open API.