Dynamic Sidebar?

        //sidebar position:
            $my_meta->addSelect('tdc_sidebar_pos',  array(''=>'default', 'sidebar_right'=>'Right sidebar', 'sidebar_left'=>'Left sidebar', 'no_sidebar'=>'No sidebar'), array('name'=> __('Sidebar position ','tax-meta'), 'std'=> array('')));

        //category sidebar
        $currentSidebars = td_get_option('sidebars'); //read the sidebars
        $categorySidebar = array();

        $categorySidebar[''] = 'Default sidebar';
        if (!empty($currentSidebars)) {
            foreach ($currentSidebars as $sidebar) {
                $categorySidebar[$sidebar] = $sidebar;
            }
        }

        if (count($categorySidebar) > 0) {
          $my_meta->addSelect('tdc_sidebar_name', $categorySidebar, array('name'=> __('Category sidebar','tax-meta'), 'std'=> array('')));
        }
        $my_meta->Finish();
    }