Macword has a short article stating that Apple announced that they’re delaying Leopard until October. Apple attributes the delay to needing to divert key OS X resources to work on the iPhone. They say they’ll show developers a “near final” version at WWDC in June and let them take home a beta copy to do their final testing.
In their press release Apple said:
iPhone has already passed several of its required certification tests and is on schedule to ship in late June as planned. We can’t wait until customers get their hands (and fingers) on it and experience what a revolutionary and magical product it is. 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(R) 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. We think it will be well worth the wait. Life often presents tradeoffs, and in this case we’re sure we’ve made the right ones.
And Bloomberg had the business angle.
Think Secret had the related story of a new beta build of Leopard being released to developers.