I kind of get the feeling you're trying to push dub to use ASON.
My first reaction is, please don't invent yet another markup language for developers to learn. Especially as this new language is only relevant to dub. Honestly it would seriously make me not want to use dub. Just pick one of the existing ones, Yaml, Json, SDL (i've never heard of this one.) and stick with it. All other package managers seem to do just fine. Don't fix what isn't broken.
Seriously though are you also willing to break all existing dub.json files? That's 317 (http://code.dlang.org/ as of today) packages this change is going to mess with. Are you really going to do that? Just as things are starting to take off?
I'm in favour of just sticking to plain, normal old Json. Everyone knows it, everyone understands it and everything else does just fine using it.