What changed my mind about node.js was when I ran a demo program as a daemon and then forgot about it for months. And it never broke.
Despite the program being very poorly constructed (by myself, of course), it was still running reliably on the machine much much later. It's a simple websocket (faye/bayeux) demo that allows multiple users to edit a grid concurrently.
Plain version: http://faye.pp19dd.com/ - works on iphones and such, and a HAL 9000 babylon.js version: http://faye.pp19dd.com/index2.php (Instructions: click on squares, use mouse wheel and such to move camera.)
At some point in putting the program together, I realized that I could write modules that could work on both the client and the server without any modifications. IE: client, server data structure. Maybe I'm rusty these days, but mind was partly blown.