The update will be rolled out gradually across all the models starting from Lumia 510 to Lumia 900 during February. Announcing the update Nokia said, "You can transform your Nokia Lumia with a host of exciting new personalization features, such as the ability to resize your tiles, new lock screen options, and more theme colours."
Users will be notified as soon as the software update is available on their phones – first it will be users having unlocked phones as Nokia will probably be looking at approval from telecom operators before it releases it to locked phones. Nokia is asking users to ensure that notifications are switched on so that they don’t miss out on the update.
The Lumia maker is not going to release the update over the air (OTA) and hence users will have to plug in their devices into the computer and use Zune to update their handsets.
Some of the features of the Windows Phone 7.8 are customizable smart screen; resizable live tiles; new lock screen; Internet sharing; Bluetooth sharing along with apps like Contact Share, Play To and Nokia City.