I hate when people make the assumption that learning JavaScript is somehow a limiting factor. It hasn't stopped me from picking up Java, Ruby, Python, or PHP. I still have some trouble with Go structs and I still have some learning to do on Rust lifetimes... but seriously.

What "next wave" of server application development does Node.js leave me so woefully unprepared to deal with? Are people really having issues marshalling JSON/XML or sending templates down the wire?