I'm not a GPU driver or graphics programmer, so I'll do my best. Hopefully someone more knowledgeable can chime in if I mess something up.
* Last May, Nvidia open-sourced their proprietary kernel module, after moving their proprietary bits into a firmware blob that runs on the GPU itself. As is, this module is not suitable for being mainlined into the Linux kernel, but acts as a starting point for a proper FOSS module.
* Nouveau developers have been able to use code and knowledge from the open-sourced Nvidia module to improve their mainlined kernel module (more low level hardware access, the ability to load said firmware blob, and the ability to control clock speeds/power states).
* The improved, actually useful Nouveau has allowed for the development of a performant user-space Vulkan driver for Nvidia called NVK, which was mainlined into Mesa a few months ago.
* Today's news is that NVK is now Vulkan 1.0 conformant, which means properly written apps that use the Vulkan 1.0 featureset should work and be performant using Nouveau and NVK/Mesa