Let's think about data typing: "a string is a string is a string", and not some weirdly marshalled byte array (which may be influenced by Marshaller, protocol value wrapper, phase of the moon, etc). Protocols would say "this is a string" (e.g. REST via Content-type: text/plain, InVM by just storing a java.lang.String) and the server would store it in an "as-native-as-possible" format, recording the type along with it. When someone retrieves it it needs to be translated to something the client understands. Obviously if I'm going to have a Cache of Strings, that metadata would be "global" to the cache and entries would not have that information.
Was this ever planned ? Canned ? Banned ?
Never planned. But makes plenty of sense. We should discuss this as a part of ISPN-2281, which addresses format portability.