FYI: I'd just like to point you to following two forthcoming standard parts from "ISO/IEC JTS 1/SC 32" comittee: one on JSON, and one on "Multi-Dimensional Arrays" (SQL/MDA).
They define there some things different as already in PG. See also Peter Baumann's slides [1] and e.g. [2]
Can be nice if we can write API with respects ANSI SQL. The main problem is query language - we doesn't support JSONPath. But if we have a own regular expression library, probably we can have i own implementation of JSONPath