I do not understand how this really any different that what we already have with anonymous classes/interfaces. If we have to continue to define interfaces for

I do not understand how this really any different that what we already have with anonymous classes/interfaces. If we have to continue to define interfaces for our lambdas then we might as well continue to use anonymous classes and remove the final restriction (that's completely backward compatible). The final restriction wasn't required in the original design of anonymous classes before the community freaked out over memory allocation of primitives. The reason closures are a pain in Java is having to meet the static typing declarations using interfaces for our anonymous classes. The whole point to this was to create a compact syntax for declaring methods that take lamdas as parameters without resorting to interfaces. I also wish that default mechanism could be extended to existing classes as well so we could add methods to classes because the real question is what are the API changes to collection, File, etc with respect to the addition of lambdas. The places where Java has fallen short in the past is the API (Collection.join? Collection.map, Collection.reduce, new File( String... paths), etc).