one group of Android phone makers is swinging towards locking their hardware down, Sony Ericsson is resolutely headed in the other direction. The Swedo-Japanese consortium has just announced it will provide a secure and legal way for eager Android hackers to gain full control of the bootloader on some of its upcoming 2011 Xperia line of phones. All four models are covered, the Xperia Play, Neo, Pro, and Arc, however you have to make sure you buy a handset that isn't SIM-locked to a carrier and then there are territorial considerations to take into account. Warranties may still be voided by fooling around with your Xperia's software (again, depends on individual handsets and markets) and SE warns gravely of the potential for "physical injuries or material damage" if you freak your Android into overheating or worse. So proceed with caution, but know that Sony Ericsson is by your side*.
* Subject to terms and conditions, repair charges may be incurred, Android upgrades are promised but never guaranteed.