At an event in Barcelona before the opening of Mobile World Congress today, following months of rumour, speculation and leaked images, Sony Ericsson formally announced that the PlayStation phone, dubbed the Xperia Play, will be released worldwide in March 2011. Sony Ericsson announced that the Xperia Play will run the Android 2.3 'Gingerbread' operating system when it ships. It also confirmed that the US would be one of the first markets to receive the device in early Spring, through an exclusive partnership with mobile network Verizon. There are still a few grey areas to Sony's launch though--no price has been announced for any market, while the PlayStation Store, through which consumers will buy and download games, will not launch until the end of the year. The device will be able to run HD games at 60 fps, according to the manufacturer. Sony Ericsson boasts the support of Electronic Arts, Namco Bandai, Glu Mobile, PopCap and Gameloft in terms of software. This will mean titles from the Guitar Hero, Battlefield and Dead Space franchises will quickly find their way onto the handheld, Sony said. Kaz Hirai, Sony Computer Entertainment's president and group CEO, was also on stage at the event to announce that the Xperia Play will launch with one "legendary PlayStation One title," although he didn't confirm which title it would be. One other partnership confirmed in Barcelona was with Unity Technology, who provide development tools to many web-based and mobile development studios. According to Sony Ericsson, Unity has pledged full support for the Xperia Play, meaning some 350,000 developers will be able to start transferring their 3D games to the device. GameSpot UK is in Barcelona to see the Xperia Play as well as find out more about the launch plan from Sony Ericsson itself. Stay tuned for more news and video as we get it.