The new prototype Sony Ericsson Shinobu X-123i is the proto of the W850, this new phone from Sony Ericsson looks really good. The Shinobu X-123i walkman phone is only a slim 12.5mm and also has features such as a 2 megapixel camera, HSDPA data connection and a nice polished face finish.
Apparently this could come to the market sooner than we think and hopefully the end of May and at around $680.
Source — Slashphone