The iPad could be Apple's key to outselling much of the portable computing market, DisplaySearch said in its latest report. Opting to include the iPad the same category as notebooks, the group expects Apple to ship nine million tablets in the second half of the year and to immediately vault over ASUS, Lenovo and Toshiba to become the fourth-largest portable computer seller in the world. Going Mac-only has previously kept Apple stuck between sixth and eighth place.