If you were counting on Leopard gaining an advantage from shipping before Vista, it looks like you're out of luck. Vista is in its last test release before shipment, and historically, the final release candidate becomes the supported RTM (ready to market) product. OEMs and volume licensees are expecting November delivery of the finished Vista, and the onesie twosie, shrink-wrap buyers will see Vista early next year. Subscribers to MSDN (Microsoft Developer Network, Microsoft's counterpart to the paid flavour of Apple's Developer Connection) will probably get the RTM code sometime between those two dates.
I'm not being too cynical, am I, to suppose that despite all the long faces and equivocal mumbles by MS execs when asked about Vista availability, November was never really in doubt? I mean, it is nice to have your bases covered; no one would have been surprised or disappointed if Vista's initial deliveries to VIPs slipped into '07. But Microsoft has been telegraphing impending availability to partners, developers and even end-buyers with marketing campaigns that talk up Vista as though it's already gone platinum. It might as well have. Microsoft has pressurized the pipeline by teasing buyers and developers with seemingly uncertain availability. The media's shameless mockery of Microsoft for having blown Longhorn/Vista targets time and again has helped generate pent-up interest in Vista by turning mere delivery of the OS into page one news. (watch the headlines; the word "finally" will work its way into a lot of story titles)
To the dismay of so many observers, when Vista goes RTM, it'll explode. It'll shatter every standing record for software units and revenue in a given period of time. It'll bury everything else in a mudslide of press coverage, and it'll even make story number four or five in non-technical publications and network news. I predict a BusinessWeek cover.
One could say that Vista's got a greased track to record sales: PC models that currently ship with Windows XP will begin shipping with Vista. Perhaps Microsoft will offer an install-time choice between OSes the way it initially did with Windows XP and Windows 2000 Professional. In any case, every PC with Vista pre-installed, even if unused, counts as a sale. I'm not suggesting there's anything dishonest about this. I'm just preparing you for mind-boggling Vista numbers in case you might find such statistics disturbing.
So Winter will be all about Vista. Where, oh where does this leave Apple? When Vista reviews start running, we'll see the professional and lay media pile on with the predictions of doom for OS X and the "too little, too late" Leopard that journalists have never seen outside Apple. Vista is it, and Macs are at a disadvantage for not shipping with Vista. Journalists of that ilk will null the value of OS X and insist that the true cost of a Mac is the machine plus the copy of Vista that really makes it work. There will be plenty of reasons for the Mac faithful to sound a call to arms.
Journalists love to proclaim the ends of eras and the dawning of new ones. For example, the fact that Intel shipped Core microarchitecture CPUs meant that the sun has set on AMD.
The media wags and flame-baiters will have a nice run through early January until Macworld Expo shuts them up. Steve Jobs had a wink in his voice when he projected Leopard's spring delivery during his WWDC keynote.
For Apple, there is no spring (the tune, "in heaven there is no beer" inexplicably just came to mind). Apple has exactly two opportunities per year to draw mass press and public attention: January and August. I suppose that Apple could view some combination of 64-bit MacBook Pros, eight-core Mac Pros and probably the announcement, but not delivery of SAS/SATA Xserve RAID as a full marquee for Macworld Expo. But I think it would be a strategic problem if a full round of 64-bit gear went out with Tiger, with Leopard held out almost as a Vista-like tease (and a fee-based upgrade for very recent buyers).
Apple's senior vice president of software engineering, Bertrand Serlet, who I think is the sharpest knife in Apple's executive kitchen, laid the foundation for a Vista vs Tiger battle with a funny and convincing comparison of Vista's GUI and its few bundled apps with the Tiger GUI and app features from which Vista's great ideas were derived. Serlet's message was that even if Vista lands before Leopard does, Tiger will still show Vista to be a derivative work. Seen another way, Serlet's presentation was meant to show that Microsoft had plagiarized elements of Tiger while Apple had already gone several laps past its own best OS/application environment.
It's interesting that although Microsoft borrowed heavily from Tiger's look and feel, Microsoft didn't capture the human-factored behaviour that spawned Tiger's visual elements. At its heart, Vista is Windows, plus a collection of modernized UI widgets for developers and a bucket for the marketable ideas that emerged from Microsoft Research. Tiger and Leopard bake consistent behaviour, look and feel and integration into everything from its dev tools to its browser. Vista can't go there: Windows will always be an operating system. Don't get me wrong; Vista is a huge step for Windows, a real godsend for those stuck in the Windows XP rut. But Apple will retain the state-of-the-art title, and applications will still rank it number one in their compendium of best places to live.
Oh, and did you catch the quip in Steve Jobs' WWDC speech about Leopard not requiring on-line activation? I wonder if journalists bring this up. Perhaps the best of them will go searching for Apple Genuine Advantage or its like and marvel at its absence. I expect, though, that we'll read the supposition that Apple's IP protection for its client platform is covert.