To be honest, given the Sony Ericsson Q3 financial results, I'd be more surprised if the company wasn't working on one of these...
While all the specifics aren't known as this stage, the phone is currently codenamed the 'Hikaru' (probably a better name than the uninspiring number and letter combo it will inevitably be assigned) and will match up its eight megapixel snapper with 8GB of onboard memory. Talk at this stage also suggests the Hikaru could be the potential successor to the attractive but flawed W960 and carry Walkman branding.
Consequently Unwired has created this very nice mock-up based on their information.
Major factors like size, weight, physical Qwerty keyboard or no physical Qwerty keyboard, price and availability however all (understandably) remain up in the air at this stage, but I'd suggest if Sony Ericsson does want to get back in the black it needs the Hikaru out in time for Santa Season to put a dampener on LG and Samsung's comparably perky festive plans.