Just a follow-up. I’ve now got Mambo using the WP template system. The only conflict is the is_email function. It’s defined by Mambo and WP. So I changed the content.php file in Mambo so that it’s is_email is now mos_is_email. Not sure what ramifications this will have on the functioning of Mambo yet.
Creating the index.php for Mambo that ties into WP is pretty simple, just start with
<?php
require('yourpath/wp-blog-header.php');
?>
<?php get_header(); ?>
and put all the Mambo content in the body. If anyone’s interested, I could post a working template somewhere.