as far as I know, at the moment there's no any official extension for eZ publish and InDesign, but I think that there is some solution around the world, that developers and eZ partners integrated for their customers.
As Opencontent, we have also implemented a very simple XML-based solution:
http://www.youtube.com/watch?v=Mdf0hISRaLg (from the 2nd minute)
it works, but it's really nothing special; I'm also very interested to see other experiences and extensions.
All the best,
gabriele francescotto
OpenContent [free software solutions]
via Verdi 19, 38100 Trento (TN) Italy
www.opencontent.it
skype : gabricocek1
twitter: gabricocek
it depends a lot by your customer's workflow and by some precondition.
From my experience, if:
the structure of your customer InDesign's templates are based on boxes
your customer is available to “tag” every single box in his InDesign templates
the customer can manage his activity using a limited number of templates
then you can export the content from an InDesign page to an XML file (manually or automatically, using InDesign server), whose structure can be something like:
