I use Node.js for several jobs on my web apps and so far everthing\'s ok.
But the Node.js uses Google\'s V8 as the default Javascript engine (JSE) and V8 runs exlusively
There is an implementation of Node.js on Rhino called Rhinodo by MuleSoft.
But you no longer have to use Rhino as a backend for Node.js - there is a recent port of Node.js and V8 for PowerPC by Andrew Low (IBM).