Plus, Apple was seriously burnt at their last little iPod do, the one with the hi fi and whatnot, nobody wants another underwhelmaton, least of all Jobs.
Yixian has a great point, but I think a new macbook/pro update is wishful thinking for the 9/9 event. Strategically, the best time to relase new comps would be october/november for the holiday shopping season. Septemeber is probably too early in their books.