A UNL theme for wordpress has been created. It requires the UNL_Templates PEAR package.
See it in action:
If you have any problems, write back here... the files are stored in the SVN server on gforge:
Checkout the files from SVN and place them in your wp-content/themes/ directory.
[UPDATED 2009-11-10, fixed broken links, change CVS reference to SVN repository]