We often tends to compare JSON against XML, i.e. JSON is simple, XML is not so simple. JSON is light, XML is heavyweight, etc. But there are still reasons to prefer, in certain cases, XML over JSON : e.g. transformation capability, XML extensibility, validation, ...
A question I sometime get when I talk about JSON-P support in Java EE is what about Schema? The works around JSON Schema standardisation is progressing but right now, this is still a draft specification. Nevertheless, this is something that you can already start to use. For example, this post shows how-to generate JSON Schema with Eclipse Link MOXy today.
As said earlier, the JSON Schema space is evolving, there are works that needs to be done at various levels but we can expect, over-time, an improved support for JSON Schema in the Java ecosystem.
