http://www.dpreview.com/previews/panasonicdmcg3/
http://www.fotopolis.pl/index.php?n=12779
http://www.imaging-resource.com/NEWS/1305187290.html
"So between the G2 and G3 sensor at ISO3200 and ISO6400 and we have a 6 decibel and 9 decibel improvement. Of course it depends on the shooting condition so that's in the best case. Nevertheless you can see that compared with the previous model we have made a big improvement. From the Raw file we apply the resolution process first, and then we apply noise reduction and put the two together to help the image quality. So at the same time we have both fine detail and low noise. The image quality is very, very close to our flagship model the GH2 – and we still have a month to improve further."
with the G3 we can offer that image quality on the same level as a GBP 600 DSLR at the higher ISOs – ISO1600 and ISO3200."