Node.js v5 is an intermediate feature release line that is best suited for users who have an easier time upgrading their Node.js installations, such as developers using the technology for front-end toolchains. This version will be supported for a maximum of only eight months and will be continually updated with new features and better performance; it is not supported under our LTS plan.
They’re calling the odd numbered version releases “stable”. Which is model similar to Ubuntu. I’m interested to see how well this plan plays out in the long run.