Hello,
you could use a news-post as wysiwyg-article. (
http://nettest.thekk.de/pages/posts/leer12.php )
The Menu-entry is a page from type 'menu-link'. It's somewhat tricky to find the correct link, and the (original) search-function doesn't perform well on this

, but it's usable.
- Add a page from type 'news'
- Create a news-post - use the 'long'-field as your wysiwyg-page
- activate commenting
- change the settings: remove the text from "Post Header" and "Post Footer". Maybe you have to change the content from some other fields, too.
- figure out the path to this posting ("e.g. /pages/posts/heading_a123.php")
- change the visibility from this news-page to hidden
- create a page from type 'menu-link', using the link from above ("/posts/heading_a123") without "/pages" and ".php"
- you can add more news-postings and menu-links
thorn.
Edit: I can't recommend this - it's very tricky to handle.