We saw the Sony Xperia go Android 4.0.4 Ice Cream Sandwich update roll out on Sunday, the Xperia sola update started yesterday and now last but not least to the ICS party is the Sony Xperia U. For now, firmware is only rolling out for the ST25a version of the Xperia U, at least for those with unbranded handsets in Australia.
For those with the ST25i version of the Sony Xperia U you have two options: 1) wait for the update, it can’t be too much longer now that the ST25a ICS update is out, or 2) use FlashTool to flash this update to your phone. If you go for the latter, the FTF file has already been uploaded to xda-developers. ST25i users need to make sure you tick the “Exclude baseband” option in FlashTool before updating.