New software update is now rolling out for the Nokia Lumia 920, 820, and 620. According to the Nokia Developer page, this software, version 1232.5957.1308.00xx, includes further performance and stability improvements, enhancements to display stability during a call, and improved automatic display brightness adjustment.
The Nokia Lumia 620 is also receiving a software update that will include improved touch behavior and enhancements to system stability and camera picture quality. Availability and timing of the update is region dependent. The Nokia Lumia 820 and Nokia Lumia 920 on my desk are not seeing these updates yet. Maybe you’ll have better luck. You can check by going to settings – phone update.