You can already run JS on the server ...
using Rhino, you mean.
A project to make JavaScript work better with Java is being kicked off with a boost from Oracle. Oracle’s multi-language lead Jim Laskey has announced Project Nashorn, which aims to build a lightweight, high-performance runtime in Java using the native Virtual Machine (JVM). Nashorn will start from scratch, using entirely new …
Seems nonsense to me.
What has PHP got to do with Javascript in any way shape or form?
You may write a site using a JS front end and a PHP backend ... buts thats the only thing I can come up with, and that just ain't the same things as JS on the server, which is then properly discussed in the last bit of the article.