Disclaimer, my knowledge of node.js a few articles mostly summarized by this http://en.wikipedia.org/wiki/Node.js
That said, so my understanding is that it's supposed to be very quick because it avoids the overhead of threading. It puts everything into a single loop instead of doing the overhead of switching between processes.
I assume there is a reason why there is a sophisticated method of switching contexts completely in between threads. My question is, what is the benefit of having threads over the node.js approach?