Back in late January Microsoft started rolling out the Windows Phone 7.8 update for existing Windows Phone 7.5 devices, bringing the Windows Phone 8 Start screen experience to older devices. However, the roll out of the update was paused after an issue with Live Tile updates emerged for some use cases. The issue has now been resolved and Microsoft has updated the update, allowing the roll out of the Windows Phone 7.8 to resume.

As a result of this update for the update devices are now being upgraded to software version 7.10.8862.144 (rather than 8858 or 8860). This should clear the way for most of the remaining existing Windows Phone 7.5 devices to receive the update to 7.8, although it clearly means there will be a schedule slip from the originally envisioned end of February completion date (more likely to now be mid-April).
  

What's in Windows Phone 7.8?

As we previsouly noted:

The key new feature in Windows Phone 7.8 is the updated Start screen with support for re-sizable tiles (three sizes). Microsoft clearly see this as a critical feature saying that "the new Start screen is one of the easiest ways to make the phone reflect your style, your passions, and your personality". In addition, the number of accent colours are doubled to twenty, the lock screen adds support for automatically using the Bing picture of the day as the background, and there's also lock screen support for a PIN/password challenge to prevent accidental device wipes on phones connected to Exchange accounts.

Nokia are also providing a number of new and updated apps that might be considered part of the Windows Phone 7.8 update to users of its Lumia devices. These add extra Bluetooth functionality (sending / receiving media and contacts), on-device support for ringtone creation, and extra camera functionality. The apps are available in the Nokia Collection of the Windows Phone Store after the Windows Phone 7.8 update has been installed.

Change log for Windows Phone 7.8 (over 7.5):

• Provides a new Start Screen experience with re-sizable small, medium and large Live Tiles.
• Expands the number of available accent colours to 20.
• Improves the lock screen experience with accidental wipe protection features and Bing image of the day wallpaper.
• Expands Windows Phone Marketplace and Xbox Live support to new countries and regions
• Enhances Chinese front and improves the appearance of Arabic and other languages
• Provides other Windows Phone quality improvements
• Adds support for device that do not have a camera capture button

Nokia (Lumia) specific updates for Windows 7.8 devices (via apps from the Nokia Collection in the Windows Phone Store):

• Ringtone maker - create ringtones from MP3 files store on your device
• Bluetooth Share - send and receive image and audio files between devices via Bluetooth
• Contacts Transfer - an updated version of this app, which makes it easy to transfer contacts from other devices
• Contacts Share - an updated version of this app, which enables sending and receiving of contact cards via Bluetooth
• Camera Lenses - Nokia has released an updated Camera Extras and a new Cinemagraph app for Windows 7.5/7.8 devices.
     

Availability

While the latest version of the Windows Phone 7.8 update has started rolling out, it will not be immediately available to all users. Microsoft rolls Windows Phone updates out in phases in order to manage the demand on the software download servers. In addition, some device variants will get the update before others. Typically unlocked devices will receive the update before operator locked device, but this does vary between updates and markets, so it is not always possible to accurately predict when an update will become available for a given device.

If you have not already updated your device to Windows Phone 7.8 the update will be applied in multiple stages. Firstly the 8858/8860 and associated updates (exact combination varies by device variant and market), and then the 8862 update (which contains the Live Tile fix).

If you have already updated your device to Windows Phone 7.8, or have a new device that shipped with Windows Phone 7.8 pre-installed, you should receive a minor (one-stage) update to the latest version (i.e. from 8858 / 8860 to 8862), which should resolve any Live Tile update issues.

Your phone will automatically notify you when an update is available. As with other Windows 7.x updates the update is delivered through the Zune Desktop client. Nokia has a handy video, which shows how the process works and summarises the key benefits of Windows Phone 7.8: