While we wait mere days for Sony to unveil whatever it's got cooking for its smartphone arm, another mysterious phone has leaked ahead of any formal reveal. This prototype black and white handset still carries the full Sony Ericsson branding, and it's rumored to pack a 3.7-inch screen at 480 x 854 resolution. It's purportedly powered by a dual-core 1GHz processor and is, according to Xperia Blog, the successor to the moderately-priced Xperia Neo. There's the same three capacitive buttons, with an unspecified front-facing camera and a five megapixel camera rumored on the back. If Sony has deigned it worthy of a Vegas showing, expect to see some close-up impressions very soon.