Shocked!

I am waiting for the new 5DII, and I do that since 2 years ago. Yesterday, I was the main photographer at a wedding and, as always, a couple of family members also make some pictures. In the church, I noticed one of them: no flash Nikonian Hmmm Strange! My 30D along with 85 mm f/1.8 @ISO 400 cannot even dream about that, I tried and was far to dark. Outside of the church, already in the evening... Low light. The same. At one particular time, that guy and his family come to take pictures along with the b&g. After taking the picture with my camera, I have also taked a picture with his camera, again without flash. Push the button (in no flash mode, on a D40 along with 18-55 VR lens). WHAAAATTT? Oh my God! Look at the display, the picture is perfect bright, focus and sharp at f/3.5 @1/15s! I don't know what kind of ISO does he used, but My Canon is far to dark (almost black) with the same settings@ ISO 400. That was a 650 $ set up, with picture that look incredible well lighted and was inaccessible for me with my Canon set up. THAT IS painful..

So, here comes the question, from a shocked Canonier

Is that VR so effective? How much difference will be IS vs VR? What ISO do you think he used?