At Home Assistant we're very excited about Matter.

Here are some highlights for us:

Open source reference implementation: Google, Apple, Home Assistant, we're all going to be running the same code to be a Matter controller. Chip manufacturers like Espressif and Nordic maintain implementations for their boards in there too, so anyone can now have the software to produce Matter compatible light bulbs. https://github.com/project-chip/connectedhomeip

It will be cheap: The software is freely available and works with a big audience. It's the same reason Android TVs from some manufacturers are cheap, the same will be the case for Matter lights and switches.

Multi-fabric: each Matter device is required to support 5 fabrics. A fabric is a Matter network. This means that you will be able to run multiple home automation controllers at the same time. So when run into the limitations of Google Home or Apple Home, you can try out Home Assistant without taking down your old system.

Easy sharing of devices: Because of multi-fabric, it will be as easy as hitting a share button to get a device added to another fabric. See this example of Android https://twitter.com/home_assistant/status/157703612255503564...

Local: all communication for Matter is happening local between a device, a thread border router (if thread-based Matter), and the controller. Note that your controller can still decide to store your data in the cloud (ie Amazon, Google).

Supported by major systems: Amazon, Apple, Google and Home Assistant are all building the open source Matter code into their systems. It means that for manufacturers it will be easy to pick Matter as the protocol they want to support to reach most users.

Works over IP: Matter works over IP and doens't care how that IP-based device communicates. It means that you can have Wi-Fi based and Thread-based devices co-exist on your network. Thread is not required if you don't care about such devices.

Bridges are part of the standard: Devices like Philips Hue hubs are going to get an upgrade to expose all the Hue lights over Matter via the hub. This makes integrating a whole ecosystem at once into Matter very easy.

Thread: Thread is a mesh networking standard that connects to your Wi-Fi network via border routers. Where Zigbee and Z-Wave need to mesh communicate all the way to your controller, Thread messages will be delivered via Wi-Fi/ethernet as soon as possible. This means it is a lot more reliable and less traffic is going over the mesh. Expect cheap border routers (open source reference implementations) but also expect them in your future Wi-Fi routers, voice assistants, Wi-Fi connected TVs etc.

Paulus /Founder Home Assistant https://www.home-assistant.io