While Java 9 support and similar questions or simple patches to API or JavaDoc etc. should be in scope for a MR or more, some ideas for breaking API changes or major additions would go beyond a simple MR, so they likely make a new JSR for Units of Measurements necessary in the near future.
How near we shall see, but as a coincidence, the BIPM and CGPM (standards bodies defining the SI standard) have the 106th annual meeting in 2017 right after JavaOne (Oct 16-20) followed by its 107th annual meeting in June 2018. Where new definitions for the SI standard shall be finalized.
There could be no real impact on the API at least when it comes to its methods and interaction (given most parts of the SI standard are handled by the SI extension modules under http://uom.si/
) but especially the 7 SI Base quantities and related units are already in the RI or other official implementations like uom-se, so Spec and JavaDoc at the very least may change following a Revision of the SI standard.
Several EG members based on their various JCP duties (Leo, Otavio and myself, possibly others like Raj or Mohamed) are supposed to attend JavaOne, so I suggest we really use the offered EG room (wherever it'll be, JavaOne 2017 is said to be in Moscone again, but Hilton may still be the official conference hotel) and hold a formal EG F2F there to discuss a possible new JSR.
Unless you think we should actually propose a new JSR before JavaOne, but there's probably enough to do with a MR1 supporting Java 9 etc.
If started in the last quarter of this year as it won't add as many features as 1.0 a new JSR (1.1 or similar) could be realistic in the second half of 2018. Some time after the new SI standard Revision was finalized.