Somewhat surprisingly, Apple has admitted that they can no longer stick to the Leopard schedule that had previously planned this spring of 2007 as the release for the new operating system being brewed by the developers of Apple, and so you should expect it 4 months later, says Apple.
Reasons given for this is basically that Apple doesn't have enough resources -- and is being forced to shift its Leopard developer team to the iPhone to help get that finished on time. In a statement, Apple said that "life often presents tradeoffs, and in this case we're sure we've made the right ones."
Makes sense. They obviously don't have enough resources to keep both projects working simultaneously. But that's about it. Many articles are saying things such as "Apple's in deep water because they can't manage multiple projects." Well, if Apple doesn't have enough developers to get projects done on time, guess what they'll do: hire more people. It's the thing that every company does when they need to expand.
And personally I couldn't care less about the delay of Leopard, it's Apple that's frying themselves from all the bad comments that they let loose about Vista in their last demo of Leopard. If they are forced to have similar delays to their operating system, that's up to them. But we've already seen the demos, the OS has already been leaked out on bittorrent, Leopard isn't that special.
iPhone is in a more unique way, which is perhaps more important for Apple to concentrate on keeping on-target. But aside from that, meh. Whatever works.