It's the EE, I have no idea why they don't mention it in the product title, but there's no other version on Gog. Copypaste from the gamecard:
What's New in the Enhanced Edition:
Professional mod tool - REDkit beta: The REDkit is the best way to craft vast, living worlds – shape environments using intuitive tools and adapt them to your needs! Create your own RPG adventures and do it CD Projekt RED style!
Additional hours of gameplay: New major adventures set in previously unseen locations, expanding the story and introducing new characters, mysteries and monsters.
New Game Introduction and Cinematics: All new animations and cut scenes, including a new, three and a half minute pre-rendered cinematic depicting the assassination of King Demavend of Aedirn. BAFTA Award winner and Academy Award nominee Tomasz Baginski brings this key historical event to life, setting the stage for the story told in The Witcher 2.