Technical they are on the save side, as it only has a description and later for downloading the addon they do link to curse. Thus they do not host the addon.
Money wise with a matching URL and keywords it seems to me that they want to 'steal' german users looking for omen (as google by default will prefer german sites to english for a german user). Thus he will end up on their page `+ their download link bring them an extra 2-3 add impressions while not generating content themselves apart from the 'thin' review.
The OS requirement for XP/Vista is plain wrong.
Looking at the other reviews the person wrote it seems they took all top downloads for curse and generated a translated german page: Lightheaded, Questhelper, Omen, Atlasloot Enhanced, Carbonite, Recount, etc etc etc. If you look at the download statistics for cartographer they gained 200 downloads / week - and therefore impressions for themselve.
they are a quite popular german wow community site. I think it might be evil to force people not really familiar with English to go to wowace / curse / wowinterface who seem to focus on English speaking users.
Has anyone contacted them ? They also have a client that used to pull addons from the files.wowace.com server.