Node.js 8 introduces several key features aimed at improving performance and usability, including a new N-API for better native module support, updated buffer behavior for enhanced security, and an improved WHATWG URL parser. The version also integrates the Turbofan and Ignition engines for optimized memory usage and faster startup times, along with async hooks for better event loop management. Additionally, it upgrades to npm 5.0.0 and includes various enhancements such as static error codes and a native debugger.