query_posts( $query_args );
if (have_posts()) :
echo '<div class="six columns">';
while (have_posts()) : the_post();
$postcount++;
if( ($postcount % 2) == 2 ) : // skip 'even' posts
    $wp_query->next_post();
    else : the_post();

        include('post-loop.php');

    endif;
endwhile;

echo '</div> <!-- end first column -->';
$postcount = 0;
rewind_posts();
echo '<div class="six columns"> <!-- start second column -->';
while(have_posts()) :
$postcount++;
if( ($postcount % 2) != 1 ) : // skip 'odd' posts
    $wp_query->next_post();
    else : the_post();

        include('post-loop.php');

    endif;
endwhile;