If only it were this easy to extended JavaScript with a new serialization format! If the serialized text can't be assigned to a JavaScript variable, it's not JavaScript notion.

I also tried something similar a few years back when I was sick of dealing with XML and coming to terms with the required quotes.

http://xjson.org/

While it's certainly prettier to have native literals and optional quotes, it's simply not worth giving up the interoperability with JavaScript.