This first screenshot is meant to hammer home the point that screenshots are not everything. Sometimes, as in this example, they're precisely nothing.

Can't you guess?
The screenshot above shows the Spatial Finder: something that is defined by its behavior, not necessarily its appearance. The only visual difference is the lack of the oblong "toolbar widget" in the right side of the window title bars. (The Spatial Finder does not have a toolbar; that's a browser feature.)
If you followed a direct link to this page hoping to see some juicy mock-ups of the Spatial Finder, I'm sorry to disappoint you. You'll have to read the article from the beginning to understand what all the fuss is about.
I'm not going to bother showing pop-up folders or labels, since most Mac users already know how those work and can easily imagine Mac OS X implementations of those features with the enhancements mentioned earlier. Let's jump right to live search folders:

Live Search Folder
This is just a rough sketch, of course, but the elements are all there. Let's go from the top to the bottom. Live search folders look like regular folders, but must be visually differentiated somehow. An icon badge is probably a better choice, but I chose the yellow and black striped folder icon to ensure visibility. (I actually kind of like that visual theme for live search folders, but that's probably just me.)
Again, note the absence of a "toolbar" widget in the title bar. Remember that Live Search Folders are part of the Spatial Finder, and therefore have no toolbars.
To further differentiate live search folders from regular folders, the status bar area has been darkened. Like the striped folder icon, this is mostly an arbitrary choice. I'm sure readers can imagine much more aesthetically pleasing and equally distinct appearances. The status bar contains the "un-editable" status icon (the pencil with the line through it on the left) to indicate that items cannot be dragged into live search folders.
On the far right of the status bar is a "busy" status icon which is shown when the contents of the folder are being updated. I debated adding this icon at all, since the premise of live search folders is that the contents simply appear to exist, and are never seen "loading." But although that is the goal, vagaries of the real world (e.g. network lag or congestion) mean that results will not always be instantaneous, thus the need for some sort of status icon.
Next to the "busy" icon is an edit button through which the user can change the query that is used to populate the live search folder. The query dialog would probably look a lot like the current "Find" dialog.
Finally, the live search folder contents provide a glimpse of the new metadata abilities of the Finder. Columns in list view can be created for any piece of metadata, and this live search folder has chosen to include a column showing the iTunes rating for each MP3 file.
This example raises a couple questions. First, what defines the "iTunes rating" piece of metadata? Second, how does the Finder know to display the little line of star icons for this piece of metadata? The answer to the first question is that application-specific file metadata is assumed to be partitioned into domains, much like bundle identifiers in Mac OS X (or class names in Java). The iTunes rating metadata could be defined by an identifier like com.apple.iTunes.song.myrating
, for example. The answer to the second question is that the Finder's default list view plug-in is simply hard-coded to display "well known" pieces of metadata in special ways. (Third party developers could subclass and extend the Finder's default view plug-ins to provide custom appearances for the pieces of metadata from their applications.)
The last mock-up is a small glimpse of the Finder browser.

The Finder Browser
As mentioned earlier, it is indeed a brushed metal window, but this does not necessarily mean that it should be implemented as such.
This screenshot shows such a tiny fraction of the capabilities of the Finder Browser outlined earlier that it's almost pointless to include it at all. Maybe I just wanted to rile up the anti-metal-heads ;-)
Anyway, you can see the back/forward buttons, the address bar, and the iTunes-like search field in the browser toolbar area, the preview drawer on the right, and the bottom-mounted status bar. Notably absent is the shelf (which, like the Spatial Finder, is mostly defined by its behavior rather than its appearance), any custom view or toolbar plug-ins, and the customizable multi-pane metadata browser view. I hope more accomplished mock-up artists will flesh things out further.