Nokia confirm: Windows Phone 7.8 update not coming until 2013

Nokia released the windows phone 7.8 update to few Lumia 800 users. However, this was merely a test run, rather than the real deal. While a limited group of users did indeed get the update, the Windows Phone 7.8 roll-out for the general public will happen in early 2013 as planned.

Those who received the update actually own a pre-production units of Lumia 800, so they were eligible for the test version of WP 7.8. All this was confirmed by a Nokia official.

Source