According to the news Microsoft is going to reveal the details of Xbox 720 at E3 in next year. There are rumors spreading that Xbox 720 launch in 2013. Microsoft hired employees in March to speed up the development of next generation console.
But from Sony they want to continue their Playstation 3 console for ten years and they are very comfortable with their device. Sony is mainly concentrating on their next generation portable gaming system i.e Playstation Vita which will be available soon this year and they made it perfect portable system by installing great features in to that device.
Any way the two consoles Xbox 720 and PS 4 will be set to launch in couple of years and which are 10x powerful than old consoles. When these consoles will come in to the market then there will be tough challenge to game developers to build a game that has high end graphics.There are some games which are going under development by using Directx 11 and one such game is Rage for the Xbox.