I've worked as a software developer for over 15 years. I've worked at startups and I've worked at Fortune 500 companies and several in between. I've seen companies and individual developers struggle to move from one technology to another. I've seen people leap into a new technology and people who never made the leap. But, I'm convinced, it doesn't have to be a leap. Everybody can keep one foot firmly planted on one side and plant his other foot in the new technology. Porting, that is, converting a web site from PHP to Node.js, can provide both functional code and a deep understanding of Node.js.
It happened to me. I learned by porting ajaximrpg, my SourceForge project, from about 2500