Now this is intriguing. Sony has trademarked the name 'Xperia Sola', Pocketnow reports. Thanks to the Xperia moniker, we know it's the name of a phone, but exactly which handset is a complete mystery.
Could it be a forthcoming solar-powered effort? (Stranger things have happened in the world of mobile recently.) Or will the Xperia S get a new name before its March launch? Or is it the new name of the Xperia U?
The patent made an appearance on the United States Patent and Trademark Office, though it's credited to "Sony Ericsson Mobile Communications AB", complete with the address of its Swedish HQ. So maybe Sony hasn't got round to amending its records yet, alerting the patent office that it's buying out Ericsson to produce phones under the Sony brand.
The patent was filed on 30 January of this year, so Sony would've known Ericsson was on the way out, although it may still officially be conducting serious business under the old brand.
We're going to put on our speculation hat and say the Xperia S is too close to launch to get a completely new name. Okay, so working names are liable to change, but rarely following an official announcement and hands-on for the likes of us tech journos.
More likely, the as-yet-unannounced Xperia U, pictured above, will take the name (it was codenamed Kumquat during development), or an entirely new handset we've not seen yet. It's possible we'll see the Sola make an appearance at Mobile World Congress at the end of February, along with LG's rumoured quad-core effort, and more from HTC and the like.
The Xperia S is due for release in March -- as it always was, according to Sony, though Play.com initially listed it for release at the end of last month.