[itsme]

Well thought, as always.
I agree, that we are discussing a possibility for "in-line text formatting", changing the appearance of only a part of a line.

Styles are definitely the most powerful and flexible solution. It would even be possible to combine both, like existing markdown dialects do it with their HTML extensions.

What I don't like actually: the existing syntax like {highlight:this ishighlighted} or {ci:this is comment italic} let's the marked text disappear if it is not supported by a specific program. That's a crucial limitation for using several programs and Markdown handles that so much better.
As you are creating a new syntax variant, please do it better.