Dell, HP, and Lenovo are joining Acer and ASUS in ultrabook launches this fall to head off the MacBook Air, suppliers indicated late Monday. All three were hoping to embrace Intel's concept of a MacBook Air-influenced ultrathin notebook and would start mass production in September. ASUS might be the first to have meaningful production, Digitimes' sources said, with 100,000 of the UX21 due for the entire second half of 2011.
