All this talk of Microsoft's demise makes me go
First of all, for those who keep saying that MS was a fluke, a quirk, that they shouldn't exist if certain things didn't happen, etc.
Well the simple fact is that most companies that get that big don't happen that often. And they certainly are historical milestones. But people will probably talk about Microsoft's past twenty years in the same vein as US Steel, Standard Oil, etc. - all of which required a certain amount of luck along with shrewd business plans, tactics, and strong-arming. I can see in a hundred years how people may speak of Bill Gates in the same vein we speak of Carnegie, Rockefeller, etc.
Apple's biggest strength is in its software, often in spite of the hardware selection. People saying that Apple provides superior hardware on its Macs are kidding themselves - they're the same platforms now and they're all made by Intel. All the other companies use it as well. What separates them, however, is that Apple delivers a full standardized package with its biggest strength: the OS. However, that also limits sales in some ways because hardware needs sometimes trump software needs. As already pointed out in this thread, people might want a discrete GPU but don't want a larger screen. People saying that's not valid might as well say its not valid that you can't have different types of cars

Fact is, people have different needs and want it, can't get it, but it doesn't make their argument any less legitimate. And I do foresee a time when Apple realizes that if it really wants to take big chunk out of the OS market share, it will have to expand its platform and eat the ills that come with it. Look at the iPhone and exclusive carriers - not only have many governments forced Apple to unlock their phones from carriers by law, but Apple has given the perception at least that they're no longer as demanding of exclusive carriers in the future. It has been very subtle but more than a few users on these forums have noticed it as well. The reason is that they've realized that artificial limitations get removed when pressure from the market says so.
And for those who say that Apple makes the best product regardless of competition and profit - don't kid yourselves. This is the high tech industry we're talking about. Making the best product is often required to survive but the fact is, making the best profits and returns for your shareholders matters the most. And look no further than the hardware industry to see examples of this. Intel was the clear leader in CPUs when they launched the disaster called Pentium 4 / Netburst. They were selling $1000 CPUs that offered little performance increase over $500 CPUs, etc. Then AMD came along with K8 and set Intel straight. Without AMD, we would probably never have seen Intel kickin butt these days with the Core architecture and soon Nehalem. At the same time though, AMD had grown complacent with K8 and when Intel came back with a vengeance, they had their pants down and are now nearing the point where running out of business is a distinct possibility.
Or another example: Nvidia vs. ATI most recently. Just look at Nvidia's shares this past month after nearly 2 years of complete domination. Or look back in the history of Apple and their dark dark days, or even earlier when they were relatively dominating the market and fell.
As far as why Microsoft *is* in markets beyond the OS and enterprise is simple - they want to not only diversify what they offer, but expand upon the capabilities of their OS.
Yes, the PS3 is outselling the XBOX 360 worldwide and the Wii is outselling all of them as well (though I don't consider the Wii a console of the same generation actually - when you think about it, it is a unique entertainment center with no equivalent so its really in its own market, most people who own a Wii and continue to use its software aren't in the same market as the PS3 or 360 really), but what we've seen this past generation of consoles is that developers of games are no longer willing to tie themselves to platforms dictated by a company. For example, they just announced that the next Final Fantasy is going to no longer be PS exclusive - it will be on 360 and PC as well as PS3. What developers have found is that because the 360 is based on the DirectX platform and so on, ports between 360 and PC and not to mention the coding for it can be reduced and eased, reducing development costs and increasing potential market.
All the talks of destroying the 360 division is ridiculous - yes, it took forever for them to make profits out of the division, but MS has the money to cover those losses pretty easily. And most of the failure wasn't in the OS at all - it was in hardware, which MS has not had a lot of experience in. Certainly lessons learned here will help them in their next generation, as the rest of the platforms hardware was pretty damn good, it was just suffering from overheating and other issues that small systems (relative to a tower PC) all suffer from.
However, seeing as how the 360 was an end-to-end platform, and one that ushered in the era of online consoles, the XBOX division is actually likely to be Microsoft's hardware basis for the future. As the capability of consoles increasingly mirror's PC's (GPU's for the PS3 are from nvidia, the 360 is by ATI, both have CPUs now, etc.), MS can see the 360 division as a future market to bring their OS and systems, in a more closed end-to-end solution certainly, but a future market nontheless.
The same goes for Windows Mobile, which has still been making money no less. But either way, the fact is that they are using it as an extension of their OS division into new markets. All this talk that they should cut out of a lot of places can apply to them trying to compete with Google by buying Yahoo and so on, and that is certainly valid. But telling them to cut the 360 and WindowsMobile is just wishful thinking. They're far more applicable to their roots, aka their operating system, than most people realize.
As far as MS ever goes for making their own hardware for PCs, it won't happen. They make their money by selling OS licenses to major OEMs and companies - forcing people to use their hardware or competing against people selling their OS's would only be counter productive. Apple is the exact opposite of course, selling OS only tied to their own hardware but they dont' compete against any other manufacturers on their OS. But MS is where MS is today because they didn't tie their OS to any hardware. That's why they grew so fast. For those that don't remember, the advent of PCs tied OS to hardware and you really had a choice only between IBM or Apple. Then MS came along and sold an OS that wasn't limited and they basically told hardware companies to worry about the hardware, they'd take care of the software part, and the rest is history.
All this talk of MS losing their power and so on might only be applicable in the consumer market - in the enterprise market, MS is firmly entrenched. They still continue to offer the best solution in the global business and economy, and the fact is, no other companies have bothered really to compete with them. Apple has certainly made hints at challenging them, but only indirectly, and their biggest foray was really in the iPhone. And even then, they still ended up using Exchange servers and so on, simply because companies won't just move away from something that has served them well. And MS Office still reigns king in the office software suite.
Yes, Vista had a rocky first year, but they *are* still selling Vista and a lot of people that once refused to upgrade have adopted it now. Personally, my enthusiast PC runs Vista Ultimate x64 and its far more rock solid and stable than any previous Windows OS i've used. The only driver issues I've had are from my Nvidia GPU. And that reminds me, all this FUD that Vista causes driver issues is a joke. Vista drivers are mostly written by the companies and if their drivers don't work, its cause the company failed to support their product (*cough* Creative *cough*). Even Macs have to have their drivers written and supported by their respective hardware companies. Funny fact though, something like 30-40% of driver issues with Vista were caused by Nvidia's drivers
As far as what MS is going to do, in the near and long term future, I can see them developing two OS's based on the same platform / framework. One is a continuation of what Windows has been - a very open platform that has a wide range of hardware and legacy support but all the ills that cane come with that as well. But that would likely be catered to power-users/enthusiasts and business/enterprise which already has a lot of requirements that can't possibly be contained to one hardware platform. But I can also an OS tailored to end-to-end, perhaps even specified for OEM needs. Vista was a bit of a beginning of this with a lot of features that controlled the OS that were never seen in XP or predecessors, such as UAC and security measures. I can see this expanding in the future much as they've done with the 360 platform and WinMo and eventually they will converge.