Unexpected dependency on CCK?

Line 178, and onwards, of taxonomynode.module

    $types = content_types();
    foreach ($types as $type) {
      $options[$type['type']] = $type['name'];
    }

This indicates a dependency on CCK, you can change that code to:

    $types = node_get_types('types');
    foreach($types as $type) {
    $options[$type->type] = $type->name;
    }

as a backport from this