Not sure this is good news or bad news for any Xperia Android phone users. Sony Ericsson has plan to fully integrated with Facebook on XPERIA phones thole new level. Anything on Facebook such as contacts, calendar sync and single sign-on will show its face at numerous places on Xperia user interface.
Hopefully these features would be as add-on application even installed already as preinstall when we buy the XPERIA phone, we still have chance to remove it without decreasing the XPERIA phones performance. As like now in my X10 Android phone, I just access Facebook through the facebook for Android app with option don’t sync all.

However if we have this feature on XPERIA phone, we will have new stuff such as :
1. A Like button in the music player, so we can share the tracks.
2. The photos shared by your friends on Facebook now have a dedicated tab in the Timescape UI.
3. Facebook notifications now appear alongside your mised calls and text messages on your lockscreen.
4. The Android image gallery now integrates your photo albums from Facebook besides the Picasa web albums.
5. A new Media discovery widget will automatically show you the videos and music shared by your friends.
6. Besides getting synced with Facebook, contacts now have new tabs full of their likes, interests, wall activity, and photos and videos.
This feature will start integrated on the new generation of Xperia Mini and Xperia Mini Pro. So, if you buy any XPERIA phone after that, you will have one on your XPERIA phone. Also it it will be implemented on the entire 2011 Xperia lineup via an update sooner or later and most probably Q2 2011.
So this feature most probably will include on update Xperia X10 to Android Gingerbread which promised will release on Q3 2011.