UPDATE:
Almost a year has passed and now I'd definitely use node.js for live systems.
It's not ready. It sure is an awesome piece of software but it's not suitable for production use yet.
The developer of node.js himself stated in a talk, that it's probably full of bugs and security issues.
This is the talk: http://www.yuiblog.com/blog/2010/05/20/video-dahl/
He recommends that IF it is to be used in a production environment, you should place it behind a stable http proxy like nginx but he discourages doing that at all.
I'll wait for a production release and until then, play with it on my local machine.
