I followed Angela's suggestion on this and set up an editable portal at www.wikipedia.org. There are two associated pages on meta, a protected HTML template:
http://meta.wikimedia.org/wiki/Www.wikipedia.org_template
And an unprotected wikitext body:
http://meta.wikimedia.org/wiki/Www.wikipedia.org_portal
I've put up a temporary page there based on the language section of the English main page, please feel free to change it.
It seems to be slow to load at the moment, not sure why.
-- Tim Starling