Over the past few years, the netbook challenged what we thought about the notebook (or laptop) computer. Then, the tablet came along and challenged our ideas about the netbook. Now, Intel has introduced a proof of concept for a new form factor in portable computing referred to as the Ultrabook. What is an Ultrabook? Can they really gain significant market share so soon after netbooks and tablets took the tech world by storm? If you consider what an Ultrabook would be capable of, and how the basic concept is already performing in the latest MacBook Air and ASUS UX product lines. These machines promise desktop-replacement notebook performance in an extremely light and thin form factor. They're already being seen in the wild for under $1,000, and who knows how much cheaper they will be in the next few years. Will this new breed of portable computers lay the final nail in the coffin of the traditional laptop?