This will definitely turn off potential new comers to JDO since its future uncertain now... I guess next step app.
Uncertainty is part of the job as architect and designer.
We have made good experience with having a thin wrapper around
the actual persistence solution.
We are training our developers on our persistence layer instead of a
specific technology and are able (to a certain degree) to switch
the technology without much impact.
We successfully moved from the proprietary versant JVI to JDO without
doing any major change to the codebase. Of course, developers need to
be made aware of some differences, but they are still using the same
API to work with persistent objects.
I expect to do another transition from JDO to whatever-comes-up-with-EJB3.0
in the not so distant future and we are not afraid about it.