The non-touch UI would likely be the Classic shell, and they can't break backwards compatibility due to their biggest customers (Enterprise) being quite upset about the drop. The last time they did some big support drop they were hit hard (See, Vista).
There are a lot more changes beyond the ones you see in the UI's.
I think the touch UI will be for casual use. For example looking through your photo library and quickly uploading one to Facebook on your way out the door or scanning the weather and email as you're getting dressed for work.
Then when you need to do some serious, multi-tabbed browsing or write a spreadsheet, reach for the mouse and keyboard.
Meh. 1) why do i need the weather as a full screen app? that should be a part of the desktop background, as should a clock. (or on a transparent layer on top.) What can Win 8 do that Linux can't (on release)? No reason to upgrade from Win 7 if you don't have a touchscreen.
The data would show up as a tile, but if you open it it will go full screen, as with all Metro apps.
Edit: Also there are certainly more changes under the hood of the OS. There will be more info on Win8 in September with their Build Conference.
It should answer your earlier question about whether or not it is for tablets only, Dave.
There's another video going around that states that this is for all form factors and that a user can disable the touch UI and run it like regular Windows. From Sinovsky's mouth.
Microsoft still doesn't get it. Touch interfaces and mouse-and-keyboard interfaces are fundamentally different things. Trying to combine the two is a recipe for failure, just like every windows tablet has been up to now.
I disagree. This is the first time I have seen anything that makes me think a touch screen bigger than my phone can fit into my life.
The touch interface would be great for a kitchen PC - check the weather while making breakfast, see if you have any emails to check, open up Bing Maps to see how the traffic is, etc.
I could see myself using the touch interface for many things while also using a mouse and keyboard when I want to do proper computing. Or a mix of both.
I was very skeptical when I heard the rumours that Windows 8 was following the WP7 touch interface...but now I am excited. This makes a Windows tablet something I will almost certainly get now, and maybe even a touch screen laptop or PC.
If I hadn't been told this was a video of Windows 8 I might have thought this was something else. This is a radical change even with all the touch screen devices now available. While it could be useful at times it seems odd to have both touch and keyboard input on a desktop. While the "live tile" concept is interesting, it seems more like a stock ticker than an operating system desktop. I would like having the updates but not in my face. Granted it is early and the design may improve hopefully. I've always enjoyed Windows and am willing to give them a chance.