The nice thing about being able to put POD directly online this way is it's the format we use for our module documentation, so we can just cut and paste from docs. We also already know the format - we work in it day in day out, so we know that code starts with an indent, bold is B<>, and ¨aut;mlauts are E<umlaut> and so on. This reduces the Cognitive Dissonance that comes with some perl hacker coming along wanting to add something to the Wiki.
The whole Wiki concept definitely is confusing. At first I would think that it leads to complete chaos. But it doesn't seem to. A great couple of links on this are Why Wiki Works and Why Wiki Works Not.