Next.js 12.3 has been released with several key features, including Fast Refresh for .env files, improvements to the Image Component, and updates to upcoming routing features. This release enhances developer experience on Vercel by providing built-in support for environment variables, image optimization, and better performance. Environment variables can be easily managed across teams and projects, while images are optimized automatically with the Image Component, including lazy loading and caching. The latest release also introduces new features and updates that will improve Next.js integration with Vercel's infrastructure primitives, such as Serverless Functions and Edge Functions.