Ok - I've just finished setting up node on my dev server and run through the tutorials.
Cons are that it seems you're rewriting everything from the web server to the database interaction
What I'm struggling with is why you'd write a whole web app with Node. I still can't see going past LAMP as each part is maintained by that community vs Node that is trying to do everything.
Would you ever use Node as just a RESTful service but have the bulk of your site done in PHP?
Have you used Node for any of your projects and if so why and how?