Apache has left JCP. This has been a long-standing issue, right from the Sun Microsystem days. So we cannot say that Oracle has been the primary cause of this split. However, it was not unexpected. Oracle, a company that has just acquired one of the biggest open source ecosystems, is fighting for its claim on multiple fronts, like the suit against Google over Android.
This will have a deeper impact on the Java community than on Oracle itself. It is not that JCP is dependent on just one member. But if a member, which has been celebrated for more than a decade and has tremendous contibutions, leaves, it is time to introspect. The specific case of Harmony will create a lot of doubts about Java being an open standard and whether it was controlled by the community or a corporate. Unfortunately, Oracle and the Java community are two completely disparate entities, at least right now. JCP has to be attended to by the community. Or, JCP will be dead.