From my perspective there seems to be a very clear purpose: unifying the interface across platforms, which is one of the disadvantages they had when compared to Apple. With Windows 8, they will basically have the same UI for desktops, tablets and phones.

Even hotmail.com's look has been revamped into outlook.com; and not only that, but Microsoft went as far to even update their logo from 1987, to match their new tile approach.

Were all these changes necessary? Time will tell, but strategically it seems to make sense to unify the desktop experience (where they are dominant) to grow 2 of their new market segments: windows phone and tablet (surface).

Why would they want to unify DOWN to that level?

It's crazy how much a lead Microsoft had with personal computers in the 80s and how far they've fallen. Once arm starts becoming powerful enough for desktops, Windows is pretty much done and the days of the wintel tax are over. We're almost there, give it about 3-4 years.

Do you really think Microsoft is so stupid that they would expect WP7 to become an instant runaway success against their competitors, without putting even a fraction of the necessary effort into pushing it? They're realistic about their products. How do you know that Microsoft didn't achieve all of its internal goals that it set for WP7? Visible market success is only one possible goal for a company as large as Microsoft, especially with a small and isolated product like WP7. And Microsoft has clearly been driving towards it Metro-revamp for a while now (Zune HD, WP7, W8). They're a big company after all and I'm sure they do analyse likely long-term trends in technology and make plans for how to navigate the future. WP7 is only one move in a long-term maneuver.

WP7 is a great OS. Unfortunately, it has been stigmatized and beat down because A) Microsoft B) Not Apple, and C) poor marketing/strategy

I've worked with two ex-Microsoft developers, and they've led me to believe otherwise.

Neither of them worked on the Windows team, but they were around when Vista was released. From their descriptions, management seemed very confident that Vista was going to be a resounding success. Apparently a lot of the rank-and-file developers had serious doubts about the product, and management didn't want to hear it.

Granted, that's anecdotal and things could have changed since then. Somehow I doubt it though.

Hysterical, considering the very first arm machines were desktops.

I think it's quite the opposite. OS X has a very different interface from iOS. Some of the visual styling is similar, but for the most part the similarity ends there. Everything with any meat on it - the basic shell interface, the user interface controls and their behavior, even the machine's basic capabilities - is markedly different between the two platforms.

That's part of why iOS started eating up WinCE's market share when it came out. WinCE tried too hard to be like Windows and its user experience suffered as a result. A bicycle and a motorcycle serve fundamentally similar purposes. But I think we can all agree that it would be wrong to jump from that observation to the conclusion that it would be a good idea for them to have the same controls.

Windows 8 is clearly a platform intended as part of a migration from classic Windows UIs and APIs over to their (née) Metro Windows 8 environment.

This strategy is high-risk. Will their partners and the customers come along to Metro and Windows 8, or will the partners and customers continue to use classic Windows UIs, APIs and tools? And this obviously hinges on whether Metro adds enough stuff to pull customers over to it; whether to the Metro portion of Windows 8, or to the Metro Windows 8 RT ARM boxes.

This is about as big an in-your-face platform migration as has been tried in recent memory.

That's what a lot of people said when Office introduced the ribbon UI concept. It's just a waste of screen space. Menus were fine. It's reorganising for nothing. It'll be a huge retraining code. I'm moving to OpenOffice RIGHT NOW!!111!eleven!

But it turned out that Microsoft's usability guys did know what they were doing. Power users, who were the only ones really making use of a lot of the more obscure menu options anyway, adapted (and realised that their old keyboard shortcuts did in fact still work). The remaining 99.99753% of the market seem to have found that Office apps got easier to use. I don't know a single person, outside of power users, who actually tried out the ribbon-style Office for more than a few days and didn't come to prefer it. And I don't know a single company who spent the much-prophesied fortune on retraining their staff to achieve that result, either.

I'm reserving judgement on Windows 8. I think some of the incremental UI changes in Windows 7, notably the new-style task bar and jump lists, were significant improvements. There were also a few very careless retrograde steps, like completely nerfing the folder view in explorer in about fifteen irritating little ways that were working just fine before. On balance, I do prefer working on my current Windows 7 machine to my previous Windows XP one. If they can build on the improvements with Windows 8, and perhaps correct a few of the long-standing and/or relatively recent irritations as well, I suspect Win8 as a desktop OS will do just fine. If they move too much around without a good reason, break lots more little things without the new top-level UI really being much of an improvement in practice, and make it feel like a dumbed-down UI that is to tablets as dumbed-down Windows gaming now is to consoles, then I suspect Win8 as a desktop OS will be a failure and Microsoft will pay an extremely heavy price for it.

But such is the nature of progress. If everyone plays it safe, nothing ever changes, and sometimes changes really do make things better.

In many ways, though - you are right. The transition to the Windows 8/Metro environment is a lot like the transition to the ribbon toolbar. Something that is despised by pretty much everyone at the start. The question that remains is whether people (who make the transition) will love Windows 8 as much as they love the ribbon toolbar.

What makes you think this is a good idea? They are different devices with different use-cases. Why would you want the same metaphor across all of them? I don't try to drive while I'm sitting on the toilet, and I don't flush the driver's seat after I've parked the car.

That statement might only be valid for the blind users of Windows.

The OS was redesigned to fit the (new?) market...

More or less, the desktop was too difficult for 95% of the users, and just got in the way of their use-cases.