As previously announced, with Windows Phone 7.8 we’re also bringing the feature to existing Windows Phone 7.5 devices. During the development process, I used builds of 7.8 on my Lumia 900 and it felt like a completely new phone: resizable Live Tiles totally change the way I do things, providing faster access to more of my favorite people, photos, and apps.Windows Phone 7.8 also includes some other cool stuff. It doubles the number of theme and accent colors—to 20—so you can make your phone even more personal. There are also 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.
We know you’re eager to get the Windows Phone 7.8 update, and we want you to know that we’re working closely with our hardware and carrier partners to get it tested, approved, and rolled out to as many devices as possible in early 2013. As we work to quickly get this in the hands of our loyal users, we’re also striving to deliver a high-quality release and ensure a smooth transition for our widely expanded services.