My idea expands on some of the progress that was made to explorer in Windows 7 via aero snap and aero peak.
First, I would add several new views - dual vertical, dual horizontal, and I would create the option in explorer to have buttons along tool bar depicting these, as well as other favorite views.. Not necessarily all, just the views people use the most. This way, they can shift between views using a single click as necessary. Dual view allows you to see two separate folder trees, side by side in a single window.. now here is where it would get fun..
In addition to aero snap and aero peak, Windows 8 introduces aero pop, which allows for a sort of bubble like effect.. How many times have you had a single window open, and desired to copy the contents of that folder to another folder, and had to copy the desired object, go dig for the destination folder location, and then right click (in 7 the space alotted for this is pitifully small) and paste..
With Aero Pop, you can combine 2 open explorer windows together into one dual view window, by hovering your open window over top of another open window, and either pressing a button on the keyboard, mouse, or completing a mouse gesture. Then the 2 windows "pop" into one window, sort of like a bubble does when it meets another bubble..
The other thing I would add, is the ability to add favorite buttons to the explorer bar, or simply a favorite tool bar. This way, as you add favorite locations to your favorites, it does not fill up the left side folder tree, obscuring the other options, but instead spreads nicely horizontally across the top of the toolbar..
Lets see.. I would love to see built in drive virtualization in Windows 7, with the ability to create, mount, and burn ISO files to disk.
I like the idea of built in internet games.. I would expand that idea adding a few more games to the mix, and allow folks to actually type chat while they are playing.. allow for user accnt creation, and win loss record keeping, etc.. Not too much different than a lot of sites like yahoo games currently function, but allow it to be outside the browser, better graphics, and I think the draw would be huge..
Built in PDF support is long over due.. Not sure if this is possible based on Microsoft and Adobe's dealings, but it seems sensible that one should be able to view pdf's right away after installing windows..
Copy - paste - move - file transfers!!! One of my biggest frustrations, even with Windows 7, is the vague-ness that surrounds file transfers in the OS.. For instance, lets say I start moving a big file from one location to another, say 100gb. First off, Windows needs to improve on the speed of these transfers. I am familiar with some tools that increase the thread cnt on transfers that seem to perform better, however, they also seem to choke when you send large groups of files. Increased file transfer speed. Second, Windows needs to be more forthcoming about what it is doing during large transfers, state which file it is currently working on etc.. also, a pause, resume button would be very cool. Sometimes, you might be right in the middle of a big transfer, and need to do something that would require stopping the transfer.. pause would be a better option.
Nuf said for now..This is already getting too lengthy..
I would like to see a new kinda 3D desktop (You know the one where they have 4 desktops and you can switch between them 
