Nokia confirmed via its blog that owners of Nokia Lumia 510, 610, 710, 800 and 900 devices should expect to see software update notifications appear on their handsets sometime in February. Earlier, Microsoft had announced that it will roll out the Windows Phone 7.8 update by January 31, so Nokia's announcement is in line with that date.
Windows Phone 7.8 update will add new features like a new start screen UI with resizable live tiles, as found in Windows Phone 8. The update brings Windows Phone 8 branding to existing Lumia devices on the splash screen and icons for Games, Office and Windows Phone Store.
Windows Phone 7.8 doubles the number of theme and accent colours to 20 and adds other new lock screen features: the option to automatically display the Bing Picture of the Day plus the 'A1B2C3' PIN/password challenge to prevent accidental device wipes on phones connected to Exchange accounts.
As mentioned earlier, Nokia didn't reveal the exact date(s) the update will be rolled out for various Lumia models, but did confirm all phones should receive the update within first three weeks of February.
There's no word yet from the likes of Samsung and HTC on Windows Phone 7.8 update plans for their devices.