I have managed to easily integrate WYMeditor into Django's administrative interface.

Here is how I did it...

First I copied the wymeditor to my project's static-served files directory, which in my case had an URL prefix of /site/media/

There I put the wymeditor, jquery and a special file admin_textarea.js, that I have written myself consisting of:

$(document).ready(function() {
    $('head', document).append('<link rel="stylesheet" type="text/css" media="screen" href="/site/media/wymeditor/skins/default/screen.css" />');
    $("textarea").wymeditor({
        updateSelector: "input:submit",
        updateEvent:    "click"    
    });
});

This file instructs the browser to load an additional WYMeditor's CSS and to convert each <textarea> HTML tag into a WYMeditor.

In each of the Django models that I whished to set WYMeditor for, I have added the following js setting to the Admin section:

class ExampleModel(models.Model):
    text = models.TextField()     # each TextField will have WYM editing enabled
    class Admin:
         js = ('/site/media/jquery.js',
               '/site/media/wymeditor/jquery.wymeditor.js',
               '/site/media/admin_textarea.js')

That is it. If you wish to use WYM in your own Django app, just follow the steps and replace the /site/media/... with whatever your static media prefix is.