To generate automatically a .pot file necessary for translating msgids inside template files you need to get i18ndude (really easy since it was placed in cheeseshop):

sudo easy_install i18ndude

Since I'm using ArchGenXML, I already have a generated.pot file created. I've renamed this file to old.pot and ran this (in the i18n folder):

i18ndude rebuild-pot --pot ./generated.pot --merge old.pot --create MyProduct ./../skins/MyProduct/

This command builds a pot file by looking at files in the skins folder and merging the extracted msgids with the ones in old.pot. Of course, the templates need to have the i18n:translate entries inside in order to be recognized by i18ndude. Now that I have the pot file, I can use KBabel to create the translated .po files. Only thing left to do is make sure my templates use the MyProduct i18n domain. To load the catalog I needed to restart zope. If the wrong catalog is loaded, delete the catalog from the Zope Control Panel > PlacelessTranslation service and the .mo file from the <zope_instance>/var/pts, after which zope has to be restarted.

The rest of the internationalization (translated content) is beautifully covered by LinguaPlone.