dpreview.com released their review of 920's camera. They do some serious reviews of DSLRs and have started reviewing key smartphone cameras only recently. The review is more or less in line with what we (at least I) know about.
Nokia says this happens 500 times per second and results in a three-stop advantage in hand-holdability, which is on par with claims from dedicated camera makers. In other words, if you can normally hold the phone steady enough for a clear shot with a shutter speed of 1/30th of a second, Nokias OIS should keep you virtually steady down to 1/4 second. Another way to look at it: a low-light shot that would normally require ISO 800 (and all the noise that implies) could be shot at a more reasonable ISO 100 without shake-induced blurring.
Does it deliver? Nokias three-stop claim is largely borne out, with the 920 routinely delivering sharp images at 1/3rd of a second shutter speeds. You can see the OIS in action before you take a picture: the system kicks in when you half-press the shutter, and the preview image immediately snaps into a spooky steadiness, floating ghostly and immune to the usual micro-movements of your muscles.
The urge when given OIS is to push it to the extreme, and we did. The system hugely increases the number of sharp shots youll get at very slow, sub-1/10th of a second shutter speeds. That means you can afford to lower ISO for cleaner images, or in very low light, just get photographs that would be otherwise impossible to capture.
The 920s F2.0 lens gives you about a half-stop advantage over most of the competition. So for example, with lighting and shutter speed being equal, the 920 could use an ISO setting of 200, while a competitor might need 280 or more. Its not a big difference, but its an advantage.
This makes it an ace at low-light photography of stationary objects, and partially addresses the Achilles heel of every phone camera on the market except Nokias own 808: poor low light performance. OIS also helps with borderline shutter speeds that non-stabilized phones routinely use anyway. While they simply hope for the best, the 920 stands an excellent chance of delivering a sharp image.
Nokia Lumia 920 Camera Review: Connect