This concept plays around with the idea of having as much vertical space as possible, which browsers are currently competing for.
Here, the location bar has no container, until such time as the user wants to edit the current location (by typing). This allows for the navigation area to be shifted further up in the window, whilst making it easy to drag the window around.
Other modifications
Removal of the progress bar that appears in the location bar when content is being loaded, or a search is being performed. This has been replaced with a small graphic to the right of the navigation buttons. (This has also been done because Windows is somewhat inaccurate when calculating how far it is with a task.)
Because of the need to free up some space toward the top of the window, the search box has been moved into the task-bar. This is also appropriate because a search generally applies to the folder you're currently in, which is what the task-bar as a whole resembles.
The task-bar has also been split up into two sections: one for current folder actions, and another for the selected item (if any). 'Organize' has been changed to 'File' to increase familiarity.
The default folder view is now 'Content', as Explorer would display information more applicable to each item in the view, such as '139 contacts, up to date'.
Lastly, this idea has been adapted to a custom theme (see 'Attributions' below), not the default 'Aero' theme.
What do you think of this concept? Do you think it's viable? Let me know in the comments, and we'll make improvements from there.
Attributions: Fugue Icons (sligthly modified) by Yusuke Kamiyamane (yusukekamiyamane.com); Glass Onion Theme (slightly modified) by Solmiler (solmiler.deviantart.com)
Notes: Permission is hereby granted to distribute modifications of this work at any time, on the single condition that the original is attributed (via linkage) to ~Rock0.