This one came out of left field -- Sony Ericsson is going to offer their 2011 Xperia line with an unlockable bootloader via the fastbook command. They say only SIM unlocked versions of the Xperia Play, Xperia Arc, Xperia Pro, and Xperia Neo will be eligible, so carriers should be happy as well as developers and advanced users. The big question of how this will affect the CDMA Xperia Play on Verizon is unanswered, but I hope they have an equivalent solution. They also go over warranty concerns and possible additional costs for service at their blog, so be sure to read the source link to get those details.
This is a big turnaround from their policy with the Xperia X-10, which will remain locked due to legal reasons. It shows that Sony Ericsson is listening to their end users and allowing the owners of their oh-so-sexy hardware complete control of it. Let's all hope other manufacturers see the benefit in this and offer similar solutions. Now to decide between the Arc or the Neo as my next phone. [Sony Ericsson Developer Blog]