Windows Phone 7.8 rollout starts today for many devices including the Nokia Lumia 900

Nokia has begun rolling out an update to its existing Windows Phone 7.5 devices, bumping the build to Windows Phone 7.8 and promising a number of new features in the process. While the update is available today for unlocked Lumia 510, 610, 710, 800 and 900 devices, carriers will begin pushing it in February.

Nokia devices will also receive some exclusive content such as internet sharing, Camera Extras, City Lens, and more. Check the Nokia Collection in the Windows Store for more details.

Microsoft has also officially announced the upgrade, though it hasn’t specified which non-Nokia devices will receive it. We previously heard that all devices upgraded to Mango would eventually see WP7.8, so it’s still possible first-generation products like the Samsung Focus and LG Optimus 7 will see the new home screen and theme options.

If you are running a Windows Phone 7.5 handset, let us know if you’ve received the update.

Source: Nokia, Microsoft