Good news for Lumia 900 owners on AT&T. The former Lumia Flagship is destined to get WP7.8 update on 30th January itself, if internal AT&T email details leaked by WPcentral has to be taken into account. This email also has changelog of the update including that it was approved on January 7th by the carrier. Check the detailed changelog as per the AT&T internal email below,

New Software Specifications:

  • Availability Date: January 30, 2013
  • File Size: ~100 MB – device updates will be performed via PC side-load only using Zune software.
  • Data use charges against customer data buckets will not apply.
  • Software Version: 2175.2307.8858.12480
  • Baseband Version:
  • Kernel Version:  7.10.8858.136

Software Update Includes:

  • New Start Screen – This change immediately refreshes and updates the look of the customers Nokia Lumia 900. Customers will now have a start screen that is similar to Windows Phone 8. This new start screen provides users with more options to personalize their start screen. More tiles can be pinned to the start screen and their sizes can be altered between small, medium, or large. In addition the wide vertical black zone on the far right called the “gutter” has been removed.
  • New theme colors – Customers will have even more options to personalize their Lumia 900. A new theme color may be selected from many new colors that have been added to the expanded color pallet.
  • Bing “Image of the Day” Lock Screen Option: Customers may now enable the regularly changing “Image of the Day” from the Bing search screen to be automatically displayed as their lock screen wallpaper. As a result the customer will have a new lock screen image available on their device each day.
  • Improved Lock Screen accidental wipe protection: Customers will experience an enhanced lock screen that is less likely to open accidentally by an inadvertent touch on the display. This will help extend the life of the battery for customers who had experienced this issue.
  • Quality and Security Enhancements – Customers will experience greater device stability with the implementation of multiple software fixes and enhancements. Improved security fixes and enhancements have been made to protect customer information on their device.
  • Marketplace Enhancements – Customers will experience an enhanced marketplace experience and a newly optimized download process.
  • API Enhancements – Customers ability to experience the benefit of these new API enhancements will depend on OEM implementation or third party applications that utilize these new APIs.  A customer should check the download store after completing the upgrade for new OEM and third party applications. For example:  Bluetooth DRM free file transfer API,  User data migration API, Convert a local DRM free MP3 file to a ringtone API