EmailService now has Twig render email messages in safe mode
OK so it's pretty easy to pass additional variables to the email template using the email.onBeforeSendEmail event:

craft()-&gt;on('email.onBeforeSendEmail', function(Event $event)
{
    $event-&gt;params['variables']['craft'] = new CraftVariable();
});


Although I guess there are security reasons for email templates being rendered in safe mode in the first place so I don't know how much of a good idea this is...