HP has acknowledged that it's been working on a Windows 8 tablet; it just hasn't mentioned whether or not the rumored Slate 8 is part of its plans. Imagine our surprise, then, when we're told that HP's 60-second "Make It Matter" commercial ends with an unannounced yet familiar-looking tablet right at the 56-second mark. There's only a fleeting glimpse, but it shows a metallic-looking body with a large black antenna window -- the combination of which would fit in with the Slate 8's purp
