With an AST representation, one can do interesting things. Everyone could have their own custom code formatting rules, and it wouldn't have to affect anyone else. Comments would have to be included in the AST for this to work sanely.

This might even go as far as languages, though for this to work well, the code would have to cover an intersection of the functionality in all the languages "rendered" to.

(Haven't watched the presentation yet. I'm in public without headphones.)