Back in the early days of Infinispan (since our first public announcement, in fact) we always had it in mind to expose a JPA-like layer to Infinispan. Initially this was as a replacement to the fine-grained replication that JBoss Cache's POJO Cache variant offered, but it grew beyond just a technique to do fine-grained replication on complex object graphs. The fact that it offered a familiar data storage API to Java developers was big. Huge, in fact.
And Hibernate OGM (Object-Grid Mapping) was born. After initial experiments and even a large-scale public demo at the JBoss World 2011 Keynote, Emmanuel has officially blogged about the launch of Hibernate OGM. Very exciting times, Infinispan now has a JPA-like layer. :-)
To reiterate a key point from Emmanuel's blog, Hibernate OGM is still in its infancy. It needs community participation to help it grow up and mature. This is where the Infinispan community should step in; consider Hibernate OGM as Infinispan's JPA-like layer and get involved. For more details, please read Emmanuel's announcement.