Vittorio Bertocciwas kind enough to suggest the following solution, which worked like a charm (the SamplesPreReqSetup.bat did the trick):
It appears you don’t have a HTTPS binding on your machine; Visual Studio would create the site as you open the project, but without that binding the operation will fail.
It sounds like your Geneva Framework installation didn’t go well: without a healthy Geneva Framework installation, the kit won’t be of much use.
Try to execute SamplesPreReqSetup.bat as referred by C:\Program Files\Microsoft Geneva Framework\Samples\SamplesReadMe.htm, then try some of the Geneva Framework SDK samples. If they work, I am sure that the problem you report will be solved. If they don’t, I suggest reinstalling geneva framework.