No, I didn't use the dev preview. If this isnt the near final interface, they've got a lot of work ahead of them. But my misgivings about it go way, way deeper than any specific UI choice. I'm just not on board with their vision of the future of the desktop. I can see this being really fantastic on a tablet, but as far as the desktop goes, the most anyone has really said in favor of it is "it isn't that bad once you get used to it". That's been repeated over and over. I'm failing to see the reason *why* this is something I should get used to. No one had to say that about the taskbar. What's the upside? Where does this interface excel, what does it do better than a standard desktop?
To me metro has a number of interface advantages over a desktop.... just off the top of my head:
The way apps can talk to each other and with windows directly (see skydrive integration when choosing a wallpaper or profile image.... apps will be allowed to register themselves there so its not just skydrive).
A universal search that allows in app searching (its been done before but never like this)
WinRT is a significant change because it allows the above functionality (this would never be possible with desktop windows because even if the hooks are there w/o a complete redesign there would be no standard area in an app to allow this functionality)
The home screen with Live tiles also show you more information than you ever hope to see in a desktop interface (they aren't app open but you don't need to have them open to see whats happening.... now this will also not be really as useful until more apps utilize live tiles and the kind of stuff they can show)
Even the multitasking with how apps have multiple states is an improvement.... you should show things differently depending if its full screen in the 2/3 or 1/3 window. In Win7 I know I was constantly resizing windows to show me the data I am looking for while keeping it on the screen.
Now alot of the above would be possible in a desktop environment but not w/o significant change to how windows works which at that point I think you would be complaining just as loud.
At the end of the day it sounds like you are one of those people who will stick with windows 7 and the rest of us will move on. That is the beauty of it.... metro is not for everybody and if you want choose something else.
I think the primary reason they had to come out with Metro now is to push developers to bring their apps over to it. They lose on polish and user experience for now, but possibly gain later. The point where Metro meets a particular user's needs so that user no longer has to jump into classic at all for key apps is a giant leap forward in user experience. Reaching that point would take longer if Microsoft stopped right now to polish Win8 for another year.
To me the big question is: in their hurry, has Microsoft made design decisions in Metro that prevents them from expanding its power significantly in the future? For instance, can they later cleanly add the ability to show more than two apps at a time? If they haven't painted themselves into a corner, I like them making the tradeoff.
That is an interesting question.... I have to imagine they will eventually expand it to allow more but I would not expect it to ever be like windows because of the groundwork laid in win8 with the 3 app states.... they don't want to force devs to rewrite everything every few yrs.