Some people say that good things come in threes, and that certainly seems to be the case here, with news arriving of Sony Ericsson’s Xperia Arc, Play, and Neo successfully being rooted.
You’re going to need your bootloader unlock code for the process, which you can now retrieve for qualifying phones using Sony Ericsson’s website tool (you’ll need a phone that’s not SIM-locked to a carrier, and be willing to relinquish warranty coverage as a result of your tinkering). Once you’ve got the bootloader open, you can re-flash your Xperia with one of the specially-prepared images, tailored for various localizations. A quick reboot later, and you’ve got your root access.
Downloads are available now supporting the Xperia Play and several Xperia Arc releases, with the needed Xperia Neo files promised for release tomorrow.
To get cracking at opening up your Xperia, follow one of the handy how-to guides posted over on the XDA-Developers forum, linked to below.