In short, why the persistent Java library is important, is because, it allows the memory chip to retain data even after the power is removed.
For now, this feature needs to be implemented with the next generation XEON processor, which is basically built for servers. However, It is believed that Intel has the capacity to make it available to CORE processors.
The persistent feature is a big leap forward. It saves the procedure of loading and dumping data in each live session. The persistent feature does not rely on files. So it could significantly improve the reliability of servers.
It is worth mention that with the persistent library, hackers can let executable codes running in the persistent memory for infinite time. If a vulnerability of the system is exploited, it will be hard for anti-virus programs to detect and remove such a malware.
Intel launched the program in November 2017, and it is under active development. For additional resources, please visit Youtube and Intel's official website.