What happend?
Is gog still sending the "email" with the gift?
Must I wait a bit more?

best to contact the customer service
but dont expect a reply soon they will be swamped

If you checked your spam folder and the email is not there, contact support about it :-) Might take a while to get an answer. Or look here on the forums, people are still gifting codes from the stamp collection.

Thanks for the answers.
I will try to contact support.

Yeah I got my code shortly after collecting last stamp.
You can check this post, it tells how to contact support in most efficient way and get this resolved: http://www.gog.com/forum/the_witcher_2/the_witcher_2_email_never_come/post112

If you don't want to bother with support, just PM me. I can give you both the game (Witcher 2) and the movie (The Gamers), or either --- for your own use, not for trading/regifting.