Anyone who says that JDO is dead is an astroturfing FUD monger and they know it.
JDO is alive and well. The specification is still more powerful, mature and advanced than the much younger and constrained JPA.
If you want to limit yourself to only what's available in the JPA standard you can write to JPA and use DataNucleus as a high performance, more transparent persistence implementation than the other implementations of JPA. Of course DataNucleus also implements the JDO standard if you want the flexibility and efficiency of modeling that JDO brings.
