Sony Ericsson's Xperia X1 on receiving end of new firmware upgrade
Unlike most Windows Mobile phones, to find the Xperia's update, you will need to use the "Update Service" software to find the upgrade and that can be found by clicking on the source link. Once you've installed it on your device, do let us know what changes you have noticed on your phone.
Sony Ericsson Xperia X1 Specifications | Review
source: Sony Ericsson via CoolSmartPhone, EngadgetMobile