A few days ago Lumia 800 owners got some exciting news. There were several reports of devices receiving the long awaited Windows Phone 7.8 update.
As it turns out though, 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 rollout 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.
So, the update is not out, folks. Stop mashing that check for updates button, because you won't have any luck with it. Not for now, at least.
There are surely ways to force the test update into your Lumia 800, but we'd advise against it. You can brick your device, void your warranty or be permanently banned from getting new software updates via the official channels.
Source | Via