This is a great plugin. But to sort out woocommerce multiple language support with qtranslate, I am using it together another plugin called qtml (http://www.somewherewarm.net/apps/woocommerce-qtml/).
Everything is working well except for the confirmation emails sent out to the client and shop owner. The labels of the custom fields are not translated and instead reads something like [:en]blabla[:fr]blablabla.
On the site confirmation page, the fields added with Checkout Field Manager are properly translated though.
According to qtml plugin dev, it might be that the code for email sending is not passing the output through a gettext __( $string ).