Make no mistake: Lenovo is taking this Windows 8 thing very seriously. The company's first-generation of Win 8 devices includes everything from a laptop / tablet hybrid to a classic convertible laptop with a swiveling display. Then there's the Yoga. This, too, is a convertible, in the sense that it can be used as a tablet. But it's not like any convertible you used back in the Win 7 era: the screen folds 360 degrees back, turning this Ultrabook into a giant,
