The battery improvements primarily come from better integration between the hardware and software and optimisations to deep hardware configuration settings. For example, the way in which WiFi operates on the devices has been made more power efficient. These improvements are the results of active, on-going, collaboration between Nokia, Microsoft and Qualcomm.
Nokia say, that due to consumer demand, the update has been brought forward from its original scheduled date of April 18th, but it will not immediately available for all devices. The update was available prior to today in a number of test markets including India and Singapore, but will now be rolled out globally over the next four weeks.
Availability varies by product code and country (e.g. in the UK the update is now available for unbranded and Vodafone devices, but it awaiting approval for Orange, 3, T-Mobile and O2). The staggered roll out is partly due to mandatory operator testing and approval, but also because the updates must go though Zune (Windows PC) or Windows Phone 7 Connector (Mac) for which Nokia is reliant upon Microsoft.
You can check the availability for your country / product code here. To check your current software version, go to Settings > About > more information. The latest Microsoft Update for Windows Phone that you have installed is the "OS version", and the latest Nokia Update for Windows Phone is the "Firmware revision number". You can also find the product code on the back of your device's SIM card holder.
- Battery life improvements with improvements made to standby time, 3G talk time, WiFi browsing time and music playback time. There are also fixes for a number of battery related issues (e.g. some devices were not using full battery capacity).
- Audio equalisers have been modified to offer wider frequency response, including better bass.
- The Camera application's defaults have been tweaked, with focus mode now being 'Normal' and not 'Macro' (the original default was to enable easier QR code scanning, but that seemed short sighted, given the relative balance between the use cases).
- White balance issues with the Lumia 800 camera have been fixed, along with other camera performance tweaks.
- The internal Diagnostics utility has been simplified to make it more accessible to end users.
- Fix for the issue where the capacitive buttons only lit up at certain screen brightness levels has been fixed.
- Fix for issue where, in certain situations the screen was non-responsive when ending a call.
- Fix for issue that caused a spontaneous reboot in certain network conditions.
The video below walks you through how to update your Lumia phone software: