Mari 6 introduced a number of USD updates and new features. We can now export USD to other DCCs. Mari will assign to selection groups as well as export and convert textures to a render-friendly format.
We also see a new roller brush that makes it easier to roll out tiled textures onto the objects. YOu can use it for patterns like stitches or whatever else that makes sense as a tiled texture.
Another “new” or should I say old feature is the broadcaster nodes that we saw introduced in Mari 4.8 and 5. As this feature was intended as a Mari 6 feature its now also launched as a new feature in mari 6. I guess Foundry was friendly enough to backport it to all of us stuck in old pipelines.