A new report suggests Sony Ericsson is more deeply invested in Windows Phone 7 than the manufacturer has let on at this point. Rumors of a Windows Phone from Sony Ericsson date back as far as this past summer but the phone maker would not confirm its plans, saying only that it was looking into Microsoft’s new mobile OS as a possible platform for future devices. As shipments decline, however, the Swedish joint venture needs to explore new avenues that might  lead to increased consumer interest in its smartphones. One of those avenues, according to a DigiTimes report, is Windows Phone 7. Channel checks with Taiwan-based manufacturers reportedly reveal that Sony Ericsson does indeed already have Windows Phone 7 devices “in the pipeline,” despite the fact that executives have been careful with their words in recent history when discussing the platform. DigiTimes’ report does not include any information as far as specific devices, nor does it indicate when we might see new Microsoft-powered phones reach market from Sony Ericsson.