Last week Apple sucked up most of the air in the tech press with its newest gadgets, which included a long-awaited, new Apple TV. This week, Amazon has some TV box news of its own. The e-commerce giant just announced a variety of updates to its Fire TV product line. The newest Fire TV set-top box, a flat, plastic box that plugs into your TV and offers a variety of internet video content, now supports 4K Ultra HD video, a claim that Apple can't make with its own set-top box. (You'll have to be watching 4K content, on a 4K...