Mysql – xtrabackup backup grants

I'm using MySQL 5.5 + Opensuse 12.3 .
After face an issue with mysqldump (appear be a bug with OpenSuse Mysql distribution) I have looking for others backup solution.

I found the xtrabackup from percona which is very nice solution .
I tested it with successfully to backup and restore .

But, it don't appear to be complete as I expected , they don't backup the users/grants and the configuration file (my.cnf)…
With mysqlpdump I user this shell script:

mygrants()
{
  mysql -B -N $@ -e "SELECT DISTINCT CONCAT(
    'SHOW GRANTS FOR ''', user, '''@''', host, ''';'
    ) AS query FROM mysql.user" | \
  mysql $@ | \
  sed 's/\(GRANT .*\)/\1;/;s/^\(Grants for .*\)/## \1 ##/;/##/{x;p;x;}'
}

and with xtrabackup I believe I will keep using this "complement" .

Looking at xtrabackup documentation, I found nothing about this subject.

What I need to know:

1. There is some way to include this (grant and my.cnf) into xtrabackup automatically?
2. If not, running my script to get the grants and copy of my.cnf is enougth as backup from my database? or I missing something here?