Seems really interesting to me (and our niche ). I don't see that as an FBX contender. I'd rather see it as a scene-version of alembic (while considering alembic as a geometry format). FBX is trying to get original procedural data across as much as possible, and i have yet to see an exchange format that even remotely manages to support a majority of features, let alone plugins or in-house tools.
I really dig the idea of having USD + Alembic at the core of a pipeline.
The only real issue i currently see is that windows support for alembic is REALLY bad. I assume this will be similar for USD. Application support is also "not ideal".