Grigori Melnik, the Product Manager of Enterprise Library, announced that Enterprise Library 3.5 will now be Enterprise Library 4 with the addition of a Dependency Injection Application Block that will both be used to simplify the configuration of Enterprise Library itself as well as be a stand alone application block for use in winform and web applications. Although you have those developers who will continue to take punches at Microsoft for reinventing tools that are already in OSS Projects, this is a positive move to 1) help simplify P&P deliverables, 2) offer a single container across all their products, and 3) deliver the full potential of the Policy Injection Application Block.
Enterprise Library is an excellent tool for delivering infrastructure services, but Object Builder, which has been at the heart of Enterprise Library for object creation, has always been a little suspect at being overly complex and "slow" for object construction when a more simpler form of dependency injection will do. In Enterprise Library 4.0, it sounds like we will see an alternative to ObjectBuilder for consuming and configuring Enterprise Library services.
Many of the deliverables from Microsoft Patterns & Practices have needed dependency injection services. Microsoft Patterns & Practices have created several containers based on ObjectBuilder to meet those needs, each with its own features and API. To maintain consistency across all the products, a single Dependency Injection Application Block will save effort, maintain a consistent API, and allow developers to share extensions and enhancements across all solutions.
In Enterprise Library 3.0, the Enterprise Library Team provided a Policy Injection Application Block to offer Aspect-Oriented Programming ( AOP ) functionality. One of the best places to inject AOP functionality is within the dependency injection tool when serving up services to the client. The combination of a Dependency Injection Application Block that uses a Policy Injection Application Block will offer seemless and power functionality within winform and web applications.
I look forward to the new Dependency Injection Application Block in Enterprise Library 4.0.