Aiming for the best possible positioning between supersmart smartphones and monster desktops, the flagship Lenovo ThinkPad X1 Carbon is a next-generation Ultrabook, a MacBook Air killer, and the thinnest and lightest laptop around at the moment. It’s thin: 18mm/0.71″. It’s light: under 1.36kg/3lbs. It’s tough, built to military grade specs, with a carbon fiber chassis. The keyboard is full-size, backlit, spill-resistant, the display: 14″ with 1600×900 resolution. There is Dolby audio; two USB 3.0 and USB 2.0 ports; integrated, contract-free, pay-as-you-go 3G mobile access; up to 12 hours battery life, with RapidCharge to 80% in 35 minutes; and the latest Intel Ivy League chips, firmware and software inside. Coming this summer, pricing TBA. With just about every major manufacturer in the Ultrabook arena, the latest race to the top is on, with the X1 so far out in front.