This is the image you are not supposed to see! Apparently, the Toronto guys got the camera 4hrs before the show started, installed 3 firmware updates. As such I was told (too late!) that we weren't to take images as this is pre-production. I asked what about the one Dpreview and others got? They got production samples. In any case the lowdown from the tech is that the G3 does not have the same "level" sensor as the GH2. It is about 1 stop noisier. However, it is considerably better than the G1, G2, GF1 and GF2 sensor. I haven't opened the raws (I fired about 10 shots before getting shut down) but here is a JPEG.
Disclaimers: It is pre-production, it was shot through the mundane 14-42mm kit lens, I don't know what noise reduction was set.
As for the camera, I like it. It gives me most of the G1's features, but it is smaller and with the 14mm, pocketable in a coat, if not pants.