With Nokia set to unveil a new Lumia lineup next week, you could be forgiven for forgetting about the company's flagship phone from last year. However, AT&T customers still holding on to their Lumia 900s have cause for celebration in the shape of the long-awaited Windows Phone 7.8 update, which has finally been made available for all months after Nokia released it in other regions.

While some may have already installed the update through other means, all owners of the AT&T variant should be able to get it now through the Zune PC client. Windows Phone 7.8's headline features are visual tweaks that bring older devices more in line with Windows Phone 8 in lieu of a full update; these include multiple Live Tile sizes, more theme colors, and an improved lock screen with the option for rotating Bing home page images.