Translation of denied message

It would be great to have the ability of translating denied messages. Currently messages are returned with the following code:

if ($user->uid == 0) {
    return variable_get('comment_perm_message_anon', 'Login or register to post comments!');
} else {
    return variable_get('comment_perm_message_reg', "We're sorry, but you can't post comments here!");
}

Why not add t() to the above code?

Thanks.