Yes, USD support in VTK would be great. We discussed this a little bit 2 years ago.
Is OpenUSD support applicable to VTK’s user base?
Yes. It would be used similarly to glTF importer/exporter.
Are there components of OpenUSD serialization that would make sense to handle at the VTK library level?
VTK’s glTF exporter is very limited in exporting metadata but it is fine because we can add and modify metadata by a json reader/writer. If this can be achieved for OpenUSD as well then it should be enough if VTK provides mapping between VTK objects and OpenUSD scene object IDs.
What components do not make sense to support in VTK and should be offloaded to individual applications such as 3D Slicer?
It should be enough if VTK can read/write what is needed for rendering, as long as VTK provides mapping to OpenUSD scene objects. Then applications could read/write additional metadata.