Apple is very much on track to ship 1.5 million MacBook Air systems in the summer, part suppliers claimed late Wednesday. Backing analyst beliefs, they said Apple had already made 400,000 to 500,000 of the new Core i5 models in June and was keeping a "strong" volume through at least July and August. At the current rate given by Digitimes contacts, Apple would have at least 1.2 million and as many as 1.5 million Airs shipping during the summer.