The "funny" thing is that I'm currently working (on spare time) on such a thing for JSON -> [Website | PDF] without even knowing the existence of jsonresume.org etc.
I started from JSON by defining a meta-model with a certain semantic with the aim of rendering it with HTML+Javascript (and using CSS for both online and PDF printed version) but, instead, I should better have checked the web first...
By the way, I really like the "raw" JSON format for the CV/Résumé (perhaps as I have defined it)... if it wasn't for @mixmastamyk point, I'd be glad if it would be accepted as is.