With LaTeX you develop documents, just the very same as you develop C::B. ;-)
This is the beauty of LaTeX.
So the question remains. Do I need to learn LaTeX to contribute something to a Document??
The answer is No (largely). It's a tagged language. So the major portion of LaTeX code will be of pure text only. Tags are necessary only in few places. For formatting you need to know couple of Tags (should you want to format them), but that shouldn't be a big headache.
So what's the purpose of the Wiki after this documentation hits the SVN?
You can use it as an Online Documentation.
Other difference is Wiki will remain
User-Editable but the SVN doc
will not.