Well, apparently not even after GDR3 update I cannot install this app. Already talked to Samsung support, got a email a weeek later that "the technical department is looking into the problem" and after that, silence.
Christmas gift from Samsung, Ativ Beam available for download. I was able to download and install it, seems to work but I wasn't able to test it properly since I don't have another Samsung NFC phone handy. ATIV Beam