Lies, Damned Lies, and XML
Various skeptics have tried (and failed) to argue that annotation-based dependency injection results in tighter coupling than other approaches. I would argue that reams of proprietary XML code couples you to a framework more than anything, but I digress.
If you're still on the fence, Kevin B. further debunks the myths in Coupling:
Furthermore, the idea of "coupling" implies that "the one cannot function without the other." But with Guice's annotations, this simply isn't the case. It's important to understand that these are only annotations. They are decoration; meta-information. They don't, and can't, actually do anything. They just sit there, innocuously, in case tools will wish to read them, and otherwise have no effect whatsoever. They do absolutely nothing to impede you from testing your code, or from using the classes with Spring.
If you produce 3rd party libraries and you want to help Guice users use your products, but you don't want a compile-time dependency on Guice yourself, provide a separate Guice integration package. This is like providing your users with example Spring XML, except it doesn't suck.
