After using several of the betas of Leopard since WWDC last year, I must say I wasn't too surprised to read that Apple has delayed the launch of OS X 10.5 until October. Apple specifically mentioned a resource drain due to the iPhone in their statement. I'm not sure how true that is since they've known the project timelines for both products for a long time now.

Many of the new features are working well in the betas, but it just doesn't have the polish that you would expect if it was going to be ready in the next couple of months. Beta 9a410 is downloading as I type, so we'll see how much improvement there is. The Known Bugs list in this latest release is still pretty significant though.

Hopefully we'll see most of the "Top Secret" Leopard features at WWDC in June.

Apple Statement

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 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. [Apr 12, 2007]

I think their approach of waiting until it's ready to release, while frustrating for users, is the right way to go when you hang your reputation on delivering quality software. None of the release the beta and then ship a service pack mentality that Microsoft takes on such things.

http://www.apple.com/hotnews