OS X Leopard delayed till October because of iPhone
It looks like getting the iPhone out on time has taken presidence over getting Leopard out on time. Apple have announced that Leopard will not released at the WWDC 07 but instead a beta will be made available for people to take home and test.
However, iPhone contains the most sophisticated software ever shipped on a mobile device, and finishing it on time has not come without a price -- we had to borrow some key software engineering and QA resources from our Mac OS X team, and as a result we will not be able to release Leopard at our Worldwide Developers Conference in early June as planned. While Leopard's features will be complete by then, we cannot deliver the quality release that we and our customers expect from us. We now plan to show our developers a near final version of Leopard at the conference, give them a beta copy to take home so they can do their final testing, and ship Leopard in October.