This is excellent news! I have been waiting for Godot (hehe) to release this.
The new Vulkan backend is exciting for 3D projects and I am excited to try to dig into the new 2d tilemapping after work.
As well, gotta love experimental Rust support:
> With Godot 4, we introduce a new system called GDExtension. By design, it takes the best parts of creating GDNative extensions and writing custom engine modules using high performance languages such as C, C++ or Rust.