I mean come on Microsoft, you know a lot of us are still not relying on touch and you know that many of us would rather stick to the way the UI looks in Windows 7 right now. Many of us still use the mouse. I'd rather want to see programs, troubleshooting, usability, flexibility and functionality improved rather than just a fancy looking interface that actually made navigating harder for many people and have made some people give a thumbs down impression on Windows 8.
I can only hope that their next previews whatsoever will not look the way it is now.
I understand the sentiment (change is never taken well), but you ask Microsoft for improvements in programs, troubleshooting, usability, flexibility, and functionality and by and large they are going to be doing that.
Programs, having a more consistent API and UI, and making it easier for developers to create them. These programs will also be lighter and all use the same framework, making problems with them easier to troubleshoot for those of us who do such things for a living. Which brings us to the next point...
Troubleshooting, by removing another app compat barrier that keeps people running their PCs as admins (which accounts for the vast majority of the reasons you need to troubleshoot Windows in the first place!). This will leave poor drivers and badly-behaving "legacy" apps written in languages other than .NET or using the new WinRM as the rest of the cause, and while there aren't many things you can do about those, it does *significantly* reduce the costs of supporting users when the vast majority of the things that put them in peril in the first place are no longer an issue. Which brings us to the next point...
Usability, making the interface to run programs simpler with an updated "start" experience; let's face it, the start menu might be what you understand and are comfortable with, but that doesn't make it a *good* interface. Having to click multiple times to find/search for applications is not as user-friendly as type searching (Vista/Win7 start menu search), and that is not as simple as pinned items on the task bar (or, in this case, the "start" pane with it's icon grid). Just because we've used the same UI paradigm for the last 16+ years doesn't make it a *good* one, it just makes it a well-known one that will be painful to change. It should still be changed.
Flexibility, meaning you will have the same environment (and thus the same UI experience) across any and all devices, regardless of how large or small they may be, or what their function is. Apps written to native frameworks like .NET and WinRM will be able to run across multiple device types, architecture types, and screen sizes. This also means more impetus for device manufacturers to make touch-enabled devices that aren't just tablets, due to the chicken and egg conundrum. In this way, Microsoft is choosing the "egg", and allowing OEMs to create the chickens - it was the same with UAC and forcing developers to write applications that conformed to security standards, which Microsoft had been trying since the days of NT4 (and failing). Ultimately, you have to draw a line in the sand and state that this is the future of the platform, and it has real and tangible benefits for users if we go down this path (whatever that path may be - in this case, it's device form factor, hardware support, and ultimately portability and battery life). Also, the old "desktop" environment and old APIs are still available to bridge the gap for people and environments who need to do so (and it is likely that there will be ways to use this as the default environment once the final product ships, although until it does this is still up in the air), meaning you can indeed have it both ways. And with flexibility comes...
Functionality, where applications a user may use can run across devices, hardware platforms, and touch and non-touch enabled devices. There's not much that can be done with Windows at this point, especially given the nearly 20 years of backwards compatibility and the tie-in to the Intel CPU architecture and instruction set, without completely breaking the mold. The world is no longer all desktop machines tethered to a desk, or even laptop machines carried around in a bag - the vast majority of people in the first world have mobile phones with at least some "smart" aspect (if they aren't already "smart phones"), and the 3rd world isn't far behind. That genie has been let out of the bottle, and there's no putting it back - mobility, battery life, and form factor are all the wave of the future - sure there will *always* be a need for high-end machines for development, testing, and niche things like gaming (although that last bit may not be for long either, given that more hardware agnosticity in Windows means you may be able to get full Windows on "gaming" consoles in the future too, and probably not the distant future either - this would largely render "PC gaming" irrelevant). Those types of devices aren't necessarily touch-enabled today, but that's largely because there's not a market for it due to there being no real software to exploit said hardware either - Windows 8 fixes that, to a large extent. Again, it's chicken and egg - we don't have decent touch on our mainstream hardware because there's not a way to do that in either Windows or the Mac OS. Switch that up with the world's most installed OS now being touch-centric, and you have made it easier for hardware OEMs to start considering touch first (rather than touch never), as they no longer have to invest the time or money to write their own touch stack for drivers and make sure it interfaces with the OS on all of their different iterations - they simply write drivers as per the DDK to the OS (in this case Windows 8), and things work; they just provide the hardware.
Time will tell if this is accurate, or if everything I've said ends up being wrong. However, the world's largest software company has decided that apps need to get less complicated, touch needs to be a first-class citizen (not second, third, or never), and they'll be flooding the market with their OS (and OEMs will be doing the same with hardware to run it). Given successes by other vendors in the tablet and mobile space (and even touch monitors attached to a desktop - if you've never used one, you might want to reconsider) and the fact that convergence saves hardware OEMs money, they're all likely to get on board. This should drive down cost, increase the native touch app space for the OS, and ultimately make the next version of Windows less of a change than this is. Windows 7 will still be king in corporate spaces, but I foresee Windows 8 being a very large player in the mobile and tablet markets, which aren't exactly small (they may even be larger than the desktop/laptop market this year or next, if analysts are correct in their predictions).
Microsoft was always going to go where the money was, and they're going to bring developers and hardware OEMs with them. Windows 8 will be a critical success but see less corporate penetration than Windows 7 has and will, but it will very likely be a consumer / commercial success, meaning Windows "9" (whatever and whenever that is) is likely to be a corporate success as well, as hardware to handle touch-first should have saturated the market by then.
Just my 2 cents, but I find it ironic that people blast Microsoft for not making things better, and when they try to do it, they get blasted for changing the way things used to work. Either you break with the past and realize that the future of computing is *not* the desktop for most users, or you stick with what you know and get left behind. As a for-profit company, Microsoft cannot do the latter, so the former is what is *going* to happen. And given Microsoft's size and dominance of the market, they're not likely to fail, either.