Next.js 6.1 introduces improved hot reloading reliability, removes react-hot-loader dependency, and enhances codebase improvements such as moving server/build directory to the top level build and adding Flow types throughout the codebase. The Next.js codemods library helps upgrade deprecated features like the `url` property on page components to their new usage with `withRouter`. The project is now open source, allowing users to contribute to its development and provide feedback. Future updates include integrating Webpack 4 for faster build times and preparing for a serverless architecture by moving `next-server` into its own package.