Node.js is cool but I think the programming model is less than stellar. Mozilla's been doing some mind-blowingly aweesome work with SpiderMonkey. It's now competitive with V8 in terms of performance and they've added many features to JavaScript that makes it more bearable to program in - destructuring, yield, iterators/generators, let binding, etc.
I recommend that people check it out.
I had a GitHub chat with one of the Mozilla developers, David Herman (who used to work the amazing PLT Scheme/Racket group at North Eastern), and it sounds like they're going show off SpiderNode in two weeks at NodeConf. They're implementing the Node.js API on top of SpiderMonkey- you'll get all the performance of Node.js as well as all the advantages that coroutining brings for simplifying evented code.