Use WP eCommerce Variation Group description as name

wpsc-vargrp-name-desc.php

<?php

/**
 * WPSC Variation Group Name Display
 *
 * @param  string   $name   Group name.
 * @param  WP_Term  $group  Group term object.
 * @return string           Group name.
 */
function my_wpsc_vargrp_name( $name, $group ) {

	if ( ! empty( $group->description ) ) {
		$name = esc_html( $group->description );
	}

	return $name;

}
add_filter( 'wpsc_vargrp_name', 'my_wpsc_vargrp_name', 10, 2 );

?>