Not sure if the world is ready for PHP5

However I would suggest a few more class functions such as :

mysql_insert_id();
mysql_fetch_assoc() ; (fetch_array returns both associative and numbered index)
mysql_free_result(); a must!
resetNumQueries(); reset your query count, very useful for debugging purposes
saving the queries (so you can use something like fetchLastQuery()

Just a few suggestions at this point in time

Regards,
Patrick