The G series bodies are rather large and bulky, unlike the S100 which I can wear on my belt. So I believe this guy is a competitor to the S100.
However, as much as I like the idea of large sensor small cameras (and may be buying one), I'm not sure I get the point. They'll never be as good as the DSLR, and the DLSRs will never be as small and lightweight as a pocket cam.
I love my S100 for the small file size, good enough shots, GPS, quick and easy movies, metal body and ease of use. Would I pay twice as much for twice the sensor size? Not sure.