Java EE 6 introduces several enhancements aimed at improving development ease and extensibility, emphasizing a right-sizing approach with a focus on flexible and lighter weight profiles. Key features include updates to web services, improvements in EJB 3.1, and the introduction of the web profile, which targets mid-sized applications. GlassFish v3 serves as the reference implementation for Java EE 6, offering modular, embeddable, and developer-friendly capabilities.