Having played with the Release Preview I have to say that while Metro is very cool, the bipolar experience of constantly switching between Metro and legacy (?) is very not cool. I'm not sure if there was a better way to solve the problem or not (obviously Microsoft prioritizes backwards-compatibility), but right now it kills the experience for me.
If Metro apps take off we'll likely see the need to switch to legacy mode dwindle over time, but with so many of our common day-to-day apps living in legacy mode at launch I'm afraid Metro will just fade away in most users minds ala the OSX Dashboard...
Having been using win8 for around a year now (MS employee), I really haven't noticed it getting in the way. I rarely find myself using a mix of both - either I'm in metro mode or I'm in a desktop mode. If I'm on a desktop, the keyboard shortcuts (win + type anything has gotten a lot better since windows 7) work wonders. They've made a lot of speed improvements that have been really nice. If I'm in metro mode (which admittedly I rarely am, it's just not that useful right now on a desktop), I tend to stay within that modality. I think that right now Microsoft is preparing for future hardware with this release. On traditional desktops, this doesn't make sense. But on things like the new surface I can actually see it working well.
I have also used products at the companies I've worked for that 1) worked well for me and that 2) nobody else can figure out. Eating your own dog food is a good first start, but never believe it is sufficient to really understand how users will use a product.
I've had to configure my helper applications to avoid getting thrown into Metro from Desktop by accident; e.g., setting my PNG viewer to Chrome instead of picture viewer. I haven't found much to in Metro yet beyond browsing my applications, but I think the whole concept is very cool. Even on my Samsung tablet I find myself in desktop all the time...b/c OneNote is just that good.
I've been using Windows 8 has my main development machine since the start of April (developing Metro style apps). I also found the jump between Metro and Desktop initially jarring but I've gotten used to it now and it feels less unnatural.
Given that I'm spending 80% of my time in Visual Studio I definitely spend more time in the Desktop than Metro (on the tablet it's pretty much the opposite), if you're living in Desktop and not launching any Metro apps than you can almost view the Start Screen as a launcher / dashboard. Tapping the windows key to quickly see alerts, tiles and notifications and then typing to find the app you want to launch.
I think Metro can succeed on the desktop but it'll certainly need the appropriate sort of apps to do so and building apps that work well as both a full screen mouse / keyboard app as well as a tablet app is going to be a real challenge.
I agree, and I think the hype for the metro interface creates a false expectation that the whole windows 8 experience is going to be new. I was disappointed using it the first time how similar it was to windows 7. Looking at Metro, you can imagine how far they could have gone, but that really would have meant betting the company on it.
If Metro apps take off we'll likely see the need to switch to legacy mode dwindle over time, but with so many of our common day-to-day apps living in legacy mode at launch I'm afraid Metro will just fade away in most users minds ala the OSX Dashboard...