When something isn't quite (or even mostly) finished on this wiki it is usally marked with a TODO - this flags the incomplete nature of the page to the reader and makes it easier for me to find what needs to be finished.
I should mention there are two cases when TODO's don't mean I need to finish somthing:
The FrontPage and TodoSection pages clearly contain unavoidable TODO's
TODO is also used by the folks at MoinMoin, so some of the supplied pages that came with the Wiki are incomplete. check out the MoinMoin version of those pages to see if they have been completed.
Here's the current list of pages with TODO's: