Having used Node.js recently for a high volume service my feeling is it is best for lots of network communication.. but not long running or CPU/disk intensive operations. So, we're slowly transitioning to a Go backend with a slim Node.js layer to form the very friendly API while we use some RPC between the Node and Go. In this, Node.js is amazing and--I would guess--hard to beat.
EDIT: Clarify with "CPU/disk intensive operations"
I'm curious about why you say nodejs is not good for long running processes? I currently have a nodejs process running 24/7 pulling a MP3 broadcast stream and haven't had any real difficulties with it, outside anything I would expect with any other language. Granted, the process itself isn't doing anything extreme, just watching certain data in the stream. I'm just curious if there is something serious I haven't encountered yet.
EDIT: Clarify with "CPU/disk intensive operations"