Six PR1.1 Firmware variants are now available at NaviFirm for Global Version of Lumia 920. These Firmwares now cover most of the APAC, Europe markets. Australian Firmware versions for Telstra is also available. Surprisingly, Grey is listed there. So, may be Grey Lumia 920 will see a wider distribution in 2013. Though Nokia has communicated Feb 2013 as the PR1.1 release date, but the availability of nearly all market variants at NaviFirm may indicate a sooner future release.
Alternatively, one can flash their Lumia 920, tutorial for which can be found on many forums and on YouTube. But, it can be a bit risky !!
