If you've been following my blog, you might have noticed that lately I've started doing quite a lot of Node.js development alongside PHP. Based on conversations I've had in various conferences, I'm by far not alone in this situation - using Node.js for real-time functionality, and PHP (or Django, or Rails) for the more traditional CRUD stuff.
Both environments have their strong points. Node.js is very fast and flexible, but PHP has a lot more mature tools and libraries available. So in a lot of projects it is hard to choose between the two. But now you might not have to.