Microsoft announced last week that all the built-in Metro apps in Windows 8 would be updated ahead of its official launch on October 26th. The company has now started delivering the updates.
Skydrive, Maps, Mail, Calendar and People apps have been updated for all the users. Some users are reporting that Photo viewer, Sports and News apps have also been updated for them. For the changelog check this thread.
The update also brings these improvements to the new OS:
- Increased power efficiency to extend battery life
- Performance improvements in Windows 8 applications and Start screen
- Improved audio and video playback in many scenarios
- Improved application and driver compatibility with Windows 8
Source: Building Windows 8