Yes, Leopard already is a nice platform for home users, and Snow Leopard will probably be a bit faster and maybe even a bit nicer. But still, it's a home user platform and it won't grow out of that market niche.
Unless, maybe, the most unlikely event of all will happen: That Apple will open their software platform to non-Apple hardware.
As long as that does not happen, hell has to freeze over before the corporate world switches to the Apple platform. Most of you are probably too young to remember the time when the corporate world was dominated by IBM and IBM alone, and how they welcomed Microsoft - one industry standard software platform, but complete independence from the hardware vendor.
Now some companies welcome the Linux platforms as their liberator from the Microsoft "monopoly" - which they helped create in the first place.
But nobody wants to go back to the times when ONE vendor "ruled them all". Apple uses the same fifty year old business model IBM had used back in the day. This might work for cell phones and mp3 players, but it no longer works in large IT environments. As a matter of fact, it had ceased working in the early 1980s already, when Compaq sold their first "IBM compatible PC" and Microsoft licensed MS-DOS to them and later to all other clone vendors.
Nevertheless, Microsoft and IBM are still the biggest player in the world of corporate IT software and services, and that won't change anytime soon. The investments have been way too high, and there simply is no compelling reason to go away from the existing solutions. The TCO of Open Source software in real life is NOT below the TCO of Microsoft solutions, and OSS solutions are also not more reliable. And in most cases, they're not even really corporate-friendly or corporate-compatible. The best example is Sharepoint Portal and its Open Source "competition". (In case you haven't gotten the cynical joke: There. Is. No. Competition.) Microsoft understands the requirements of their enterprise customers. The Open Source community does not.
I have a long enough background in quite big global organizations and their IT requirements and demands. And when I was a freshly brainwashed new-born Apple user, I tried to convince the IT management of the blessings of Apple. They wiped it quicker from the table than I could look, and some of the - very valid - reasons I've mentioned above, about some some others I've blogged. Non-existent product roadmaps is another killer argument against Apple in the corporate world. And the software incompatibility of OS X to legacy applications doesn't help either. It's also a bit "pricy" to integrate them into a large network domain, if it's possible at all. Remote administration is another issue, as is centralized push installation of software or the rollout of thousands of machines with a pre-installed software image. It's probably all solvable one way or the other, but still the question remains whether it's worth it. In most cases, it's not, because there simply is not sufficient business-oriented software available for OS X. And not everything is going to the web, and many things never ever should.
Microsoft has received disastrous press resonance for Vista, probably mostly based upon glimpses at the 32-Bit edition of the system. Most companies are not excited about it either. Well, companies never were excited about a new software release, and they never will be. All a new software release ever is is new costs, usually at too little return of investment. And most companies never upgrade to every new versions. Most of the time, they skip one or even two update cycles. Many entities are currently upgrading to Windows Server 2003 or 2008... from Windows NT 4.0.
The bottom line here is that Microsoft is supporting its platforms over very long periods of time, and although Vista was a major architectural overhaul - especially in its 64-Bit incarnation - it still is highly compatible to legacy software. As a company, you can rely on a Microsoft solution for an extraordinarily long time axis, Microsoft's business products have something called longevity.
Contrary to that, the Linux developers change their APIs with every release, breaking existing code, and Apple traditionally only supports their last two platform releases, and they release major platform updates in average every 18 months. Sure, there are (commercial) Linux distributions that come with long term support, but they come at the price that you are locked-in to that specific distribution vendor, because the software for one does not necessarily run on another distribution without any changes. That kind of fragmentation is the worst enemy of Linux.
Linux has become very popular as the L in the LAMP stack, or as the foundation for database servers and as the software kernel in hardware appliances. It still is a disaster on the desktop for too many reasons to list here.
Linux might be eating some market share of Solaris, but SUN still is a big player in the data center. And SUN owns many of the technologies that power today's web server farms. The M in the LAMP stack being only one of them.
OS X Server has almost no significance and only very few customers world-wide. OS X is a desktop OS targeted at consumers and, to a certain extent, prosumers (in the traditional niche of the graphics design and audio/music and video editing business). That's a large enough niche for Apple to be successful enough as a corporation. But assuming that they will grow out of that niche with the current direction in which Apple's management is going is day-dreaming and wishful thinking.
If Apple wants to occupy a larger market niche - and I strongly doubt that they even WANT to do that - they have to open their platform to third party hardware vendors. It probably would also make perfect sense if they joined forces with SUN. Apple has the client platform, SUN the data center-ready server technology.
But we all know that none of this will ever happen. Besides certain reality distortion fields, there are also some megalomaniac management egos in that equation that don't play well with others.
And as long as even web browsers need an operating system to run on, Microsoft's position isn't endangered at all.
