One of the main issues with LaTeX code in an etherpad session is that some users will be comfortable with this, but many will be confused or break code inadvertently. For collaborative editing of scientific papers, it would be great to make it less confusing for editors while still having LaTeX code.
It would be fantastic to have a toggle for show/hide markup with a default for each user.
Perhaps the style of text could be used to differentiate major formatting like headers = bold
I don't think the aim should be to parse the LaTeX, just to hide it intelligently so naive edits are still useful.
Example:
A LaTeX savvy user would see:
\documentclass[12pt]{article}
\usepackage{lingmacros}
\usepackage{tree-dvips}
\begin{document}
\section*{Section one}
Once in a forest, there stood a tree next to a mushroom.
\subsection*{this is really a small point}
The mushroom was small but poisonous.
\end{document}
while a markup fearing user would see (*bold text):
Section one
Once in a forest, there stood a tree next to a mushroom.
this is really a small point
The mushroom was small but poisonous.