MySQL export user with semi-colon ";" on the end
In addition to the fact that there's not any "official" way to do this, there's another potential problem with the approach: there's no mechanism that will ever revoke any privilege for a user.

Today, user 'foo' at host 'bar' has SELECT, UPDATE, and DELETE.  

mysql&gt; SHOW GRANTS FOR 'foo'@'bar';
+-------------------------------------------------------------------------------+
| Grants for foo@bar                                                            |
+-------------------------------------------------------------------------------+
| GRANT SELECT, UPDATE, DELETE ON *.* TO 'foo'@'bar' IDENTIFIED BY PASSWORD '*' |
+-------------------------------------------------------------------------------+
1 row in set (0.00 sec)


Oops, they shouldn't have delete, so you fix that.  Tomorrow's file contains the correct grant statement:

mysql&gt; GRANT SELECT, UPDATE ON *.* TO 'foo'@'bar';
Query OK, 0 rows affected (0.00 sec)


After that's processed, what privileges does the user have?

mysql&gt; SHOW GRANTS FOR 'foo'@'bar';
+-------------------------------------------------------------------------------+
| Grants for foo@bar                                                            |
+-------------------------------------------------------------------------------+
| GRANT SELECT, UPDATE, DELETE ON *.* TO 'foo'@'bar' IDENTIFIED BY PASSWORD '*' |
+-------------------------------------------------------------------------------+
1 row in set (0.00 sec)


The GRANT statement is additive, so it only specifies what privileges should be added if not present.

I would think, then, that a better approach might be what @Mat was (I think) implying... you should script the privilege changes you want to make, then execute that script against all of the servers you want to update, rather than trying to treat one server as permissions master.