HP has appears to have leaked an unannounced tablet in a new advert entitled "Make it matter".The advert - released on YouTube - calls its customers to use the power of the company's technology to make it matter, whatever "it" might be."We don't just believe in the power of technology," says the voiceover. "We believe in the power of people, and technology works for you, to do the things that matter, to dream, to learn, to create, to work."While the inspirational words are floating into your ears, your eyes - if they are quick enough - can spot not one man using a new tablet from the company, but two, in two separate shots.Although you never see the front of the tablet, the iPad-looking device - but with a black bar and a HP logo - is very different from the HP TouchPad launched previously. Judging by the size of the device, it looks to be sporting a 10-inch screen.\u00a0Of course it could be a mock-up of what might be, but with HP expected to be releasing a\u00a0Windows 8 tablet\u00a0later this year in connection with the launch of the Windows 8 operating system from Microsoft on the 26 October\u00a0it seems a strange move not to use the final device.\u00a0Could this be that tablet? We've asked HP for clarification.We will keep you posted.