Microsoft has now officially confirmed that the WP 7.8 upgrade will roll-out to older devices in ‘early 2013′. The 7.8 update will bring the new Start Screen, Lock Screen, new theme colors and more to the first generation Lumia devices.
Bits from WP Bog:
“We know you’re eager to get the Windows Phone 7.8 update, and we want you to know that we’re working closely with our hardware and carrier partners to get it tested, approved, and rolled out to as many devices as possible in early 2013. As we work to quickly get this in the hands of our loyal users, we’re also striving to deliver a high-quality release and ensure a smooth transition for our widely expanded services.”
Read more here: http://blogs.windows.com/windows_phone