Hi,
I have this planned, but the major problem with json is then accessing data in a convenient way because json libraries do not have the Xpath equivalent search system that is found with Xml, so accessing data is tricky with json within PlayMaker.
What I think would work well is to get the json and convert it into xml, which then is all accessed using XmlMaker. I already have a converted in place, but it's still very much a work in progress.
If you think it would be useful for you, let me know, and I can clean this up and start sharing it properly on the wiki.
Bye,
Jean