Sony Ericsson issues a firmware update for the Xperia X10
The update improves the responsiveness of the UX user interface and plugs the power leaks that shortened battery life in idle mode before. Sony Ericsson also throws in a free backup application with this firmware version as well as enhanced PlayNow functionalities in several countries. Nothing snazzy, but it will keep you warm until the upgrade to Android 2.1 appears on your notification bar.
Sony Ericsson Xperia X10 Specifications | Review