[IshKebab]

Ha I really hope you're right about JSON being a fad, and something better will come along.

I would bet against it though. JSON's flaws (ambiguous spec re numbers & duplicate keys etc; no comments, strings aren't zero copy...) are pretty minor compared to XML's (completely wrong data model, insanely verbose, not even basic data types).

There was much more motivation to replace XML than JSON.

Also even though XML has been broadly replaced, it's still widespread and I don't think it would be out of place to have it in a standard library. Go has, and Go's standard library is one of its highlights.