I have a moderately complicated wiki page that looks reasonably pretty to view, but is a nightmare to update - because it consists of a series of tables with no gaps between them to add extra items as necessary. (img153.imageshack.us/img153/8028/tables.png)
Some form of text-based editing mode would allow me to copy-paste new items in between the existing ones, then edit the text. It would also make it simpler to apply certain types of styles.
I know both HTML and MediaWiki markup roughly, but presume that the FogBugz Wiki format does not use either of those (because of this). However, assuming the FogBugz markup itself isn't too complicated, even that would do - all I need is the ability to copy-paste and insert between lines. I can then do the actual text editing back in the WYSIWYG editor.