SE-Xperia wrote on Sunday that O2 UK released an OS update for the Sony Ericsson Xperia X10 that unfortunately, does not bring Android 2.1 to the device, but instead brings much sought after improvements to the performance of certain applications, as well as increased battery life. EuroDroid notes that the update is fairly large in size (153MB) and is not appearing to be an OTA update at this time.
TalkAndroid mentions that the update, Firmware R2BA026, includes enhancements "in TimeScape and MediaScape. But, watch out, there are also reports of a wifi bug in the update."
SE-Xperia noted that "at the moment, the update can’t be performed as an OTA (over the air) update. Instead users will need to use the Sony Ericsson Update Service or PC Companion to update the firmware version." They go on to mention that "the only firmware users didn’t find this a problem, was in R2BA020, so I’m sure there will be some users who wished it was the earlier firmware released onto O2."
Phandroid takes a slightly different view, suggesting that "perhaps it’s a small price to pay if you felt the phone was starting to get sluggish and if you were frustrated with battery life."
Image from EuroDroid