the mysql_close() function is not being removed -- it's just unnecessary for non-persistent connections (the PHP documentation tells you this). PHP automatically closes non-persistent connections (created with mysql_connect(), rather than mysql_pconnect()). mysql_close() will never close a persistent connection (and thus is completely unnecessary when using mysql_pconnect()).

Kiwi: unless your scripts are incredibly resource intensive, I honestly don't think it would ever be necessary to force close a MySQL connection just so the script finishes without that connection. but to each their own, if you think (or your company thinks) you need it.