Xperias with unlocked bootloaders won't get updates
When Sony Ericsson announced they will release a tool to unlock the bootloader on some of their devices, fans celebrated. One problem has come up though once you unlock, you cant get official software updates.
A Sony Ericsson developer has posted on the XDA-Developers forums answering some questions. He explains that Over-The-Air updates are not supported since they rely on updating a phone only from a specific firmware version and Sony Ericsson cant verify that your phone is using that version once you unlock the bootloader (updating from a different version will corrupt the files).
Even using the regular software update tool that can update a phone from any version is not currently supported for unlocked. They may enable that in the future, but now there are still unanswered questions as to how allowing updates for unlocked phones will affect the update procedure itself and what that would mean for Sony Ericsson repair and support centers.
Sony Ericsson considers creating recovery ROM that would allow you to put an official ROM with a locked bootloader so that you can update the phone via their software update tool. Note that even if Sony Ericsson releases such a recovery ROM your warranty may be voided even after flashing it.
Of course, once you unlock the bootloader you can always use a custom ROM to update to the latest version. But this is still an important thing to consider once you unlock the bootloader on your Sony Ericsson Xperia device, you shouldnt rely on official software updates from Sony Ericsson. You might have to pay for repairs if something goes wrong too.