Separation of Concerns / Code Injection - using Google Guice
Spring has it, Enterprise Library has it, Google's been using it. Check out a framework that Google's been using for production, now open to the public
Guice wholly embraces annotations and generics, thereby enabling you to wire together and test objects with less effort than ever before. Annotations finally free you from error-prone, refactoring-adverse string identifiers.
google-guice - Google Code