For the past couple of years, I've had an idea about what Apple should do with the Finder in Mac OS X. After the demonstration at WWDC, it's not clear whether Apple read my mind and will be giving me exactly what I want, or whether they're throwing away years of research in favor of a reflection of Steve Jobs' ego, or something in between.
One of the wonderful things unique to the Mac OS has always been spatial orientation in the Finder: the ability to take a file or a folder window, put it where you want it on the screen, and count on it always being in that position until the next time you move it. I don't mean putting files into different folders, I mean putting a group of files in the lower-left corner of a window and another group of files in the upper-right corner of the same window, and never having to worry about them getting mixed up. I'm talking about putting all your documents in the second folder from the left and not remembering (nor having to remember) what that folder is named. Resize your hard drive window so the System Folder isn't initially visible and you have to scroll down if you want to get to it. Not everyone works this way, but I've seen it time and time again - Mac users being careful to arrange their icons and windows just the way they want them, knowing they'll be there next time, just like laying out a collection of papers on a desk.
Steve Jobs' desk, however, is bare and spotless. He doesn't work this way, and seems to have trouble understanding those who do. When he browses files on his computer, he wants one single window open that lets him go wherever he wants - navigating between folders much like a web browser navigates between pages. Initial versions of Mac OS X didn't really work with spatial orientation very well - icons could get moved around unexpectedly, and you'd never know where on the screen a window would open. Fortunately, Apple listened when users complained, and these bugs have been fixed - you have to change your preferences, but you can get back the spatial behavior of Mac OS 9.
However, it is still useful to have a file browser! In 1993, Greg Landweber (best known for Kaleidoscope and other user-interface hacks) released a shareware application called Greg's Browser to fill precisely this niche. It was a hierarchial tree-based file browser that allowed users to easily navigate among folders nested several layers deep in the filesystem. However, it was not a replacement for the Finder, but a complement to the Finder. You could always quit Greg's Browser and return to the Finder, where your real files were (Greg's Browser merely showed you an abstract representation of them; the files themselves were still right where you left them).
What I've been hoping Apple will do is keep the spatially-oriented Finder concept from classic Mac OS, and ALSO have a file browser that can abstractly navigate through the filesystem. In the latest versions of Mac OS X this mostly works, if you check “Always open folders in a new window” in Finder Preferences, then open a new window set to column view, but the line between the two is blurred - any given window can be toggled between column view and icon or list view. and the results can be confusing: for example, open a folder window, move it to the lower right corner of the screen, then switch to column view, navigate to a different folder, move the window to the upper left corner of the screen, and switch back to icon view - which window have you moved to the upper left corner, if any? The next time you open those folders, where will they appear? The file browser really needs to be kept separate.
What Apple unveiled at WWDC is a new improved single-window file browser interface, with the Brushed Metal appearance to match Safari. What I don't see is the spatially-oriented Finder interface. Hopefully they're not trying to hack the two together again, or throwing out the spatial Finder altogether. What I envision is this: when you open a new window (Cmd-N), it opens a new brushed-metal browser window, which you can use to navigate in any view you want (column, icon or list). There should be Back and Forward buttons, which would behave like a web browser. However, if you double-click an icon on the Desktop, it should open into a normal Aqua Finder window, without the sidebar or toolbar or Back/Forward buttons, and should behave like Finder windows in Mac OS 9. By default, there would be no disk icons on the Desktop, so this behavior would never be encountered by those who didn't want it, and they could just use browser windows, but those of us who want the spatial Finder would have it, AND have a great file browser.
The only problem here is what to do if you move a folder to the Desktop and double-click it - does it open in its normal Aqua Finder window, or into a new brushed-metal browser window, or into your already-open brushed-metal browser window (if one is available)? This could be resolved with a preference, and overridden with a modifier key.
So, will Apple demonstrate that they really understand their users, or only that they understand Steve Jobs? We'll find out this fall!