One thing I would note on the client side of xmpp - there does seem to be a lot of work happening under the surface. Snikket is working on an SDK to streamline modern client development. There are a couple of alpha stage clients written on it already, and maturatoin of the SDK should lower the bar for pushing clients forward.

Also independently, Movim keeps advancing and Libervia is doing a ton of cool work. I'm sure I am missing others.