I am also VERY interested in making this change. I tracked it down to the getTopRated function, but it looks like it would require a complicated change to the SQL.
Will someone please help us?
$query = "
SELECT *, {$bayesian_formula} AS bayesian_rating
FROM {$wpdb->posts}
LEFT JOIN(
SELECT DISTINCT post_id,
(SELECT CAST(meta_value AS DECIMAL(10)) FROM {$wpdb->postmeta} WHERE {$wpdb->postmeta}.post_id = meta.post_id AND meta_key ='votes') AS votes,
(SELECT CAST(meta_value AS DECIMAL(10,2)) FROM {$wpdb->postmeta} WHERE {$wpdb->postmeta}.post_id = meta.post_id AND meta_key ='rating') AS rating
FROM {$wpdb->postmeta} meta )
AS newmeta ON {$wpdb->posts}.ID = newmeta.post_id
WHERE post_status = 'publish' AND post_type = '{$post_type}' {$where}
GROUP BY ID
ORDER BY {$sortby} {$order}
LIMIT {$offset}, {$number}
";