The Wiki Plugin should be a plugin that allows us to edit in wiki syntax.

related bugs

already available

where to start?
What markup? We have MediaWiki (which seems to be the most used wiki because of Wikipedia), MoinWiki and many more.
Some markup is common in many wikis. Maybe we can make this switchable via prefs?
I have recently started using LaTeXPlugin with the preview window and built in rubber, this is useful, I have also developed my own wiki syntax (based on most common versions) for easy, structured note taking, this comes with a wiki2html converter I made, but without a preview window Gedit would just serve as syntax colouring for wiki-type text would it not? Maybe this should be another syntax definition instead (as noted above in already available)?

We start with MediaWiki Syntax:

= h1 =
== h2 h2 ==
=== h3 ===
=== h4 ===

* unnumbered list
** second layer item
*** and so forth

#.

'''bold'''
''italic''