Nokia may have signed a pledge of mobile allegiance to Windows Phone, but that doesn't mean its Symbian faithful have to play the part of the spurned lover. Espoo still sees a future for users of its other OS and plans to dish out the upgrades in two future steps, bearing such '70s disco queen-from-BK names like Carla and Donna. Details of these purported updates leaked out at the company's Developer's Day in Mexico where a blurrycam slide outed the planned progression for Belle-operating handsets. So, what's on deck? Well, Carla'll be the first to hit, bringing an updated Browser (8.0 here), Dolby Surround Sound, NFC functionality and improved widgets, while Donna's party plans were less than forthcoming, indicating that it'd be an exclusively dual-core phone affair. So, clear out some space on that Symbian dance card, these solid gold gals are looking for one last spin on the mobile dance floor.