Maya 2018 is already out for subscription,
as far as I can test, this is a very solid release with many performance/stability improvement and an impressive number of Maya bug fixed.
There is a new Maya API that will prevent the need of recompilation for third party plugins in future Maya versions,
but for now we still need a new Octane plugin for Maya 2018.
Pay attention that in Maya 2018, the legacy default viewport and the legacy high quality viewport have been removed,
so all Octane features must support viewport 2.0.