Oh in the end?* None of them.* I believe that the GUI Desktop
   metaphor is coming close to the End Cycle.* I forsee the
   replacement as something *very loosely* akin to - an immersive
   environment not tied down to Documents, Files, Folders, phones,
   movies, TV, cameras analogies/metaphors. The line will blur and
   disappear between video, typing, voice, pictures, as I think it
   will be possible to receive information in the format you most
   desire. I think the emphasis will be on "views"; what you
   receive will be customizable depending on your skill level so
   that there are no barriers to human/computer interaction.
   Someone who is 7 years old will equally be able to customize
   their experience to their needs and skill levels and primary
   mode of communication equally well as a 42 year old computer
   programmer, or a 22 year old game designer, or a 70 year old
   grandparent. a) You have a preferred mode of communication.*
   Visual, auditory, mathematical, musical, tactile are the big
   three, but there are others.* There's logical thinkers,
   emotional thinkers, introspective thinkers, etc and they all
   interact with themselves and the world differently. b)* If your
   preferred output is spoken words, you would have the option to
   speak and a set of powerful translators will be able to not only
   save your content as you provided it, but it will be saved in
   all of its forms, some parts translated into different modes if
   it needs to complete the set. If you are the recipient of your
   work, you will want it back in your preferred mode of
   reception.* Example: You might like to speak to get things OUT
   of your mind, but you prefer to READ to put things in. If
   someone else is the recipient, if they prefer video, then they
   could get a video of you talking - *if* you give permission for
   that, that is. If you wish to convey your exact words, you can
   have that done. But if you wish the *idea* to come across, the
   computer will be able to translate that into analogies that,
   with your approval, would be transmitted. Example: If someone
   understands things better in a line drawing cartoon form, your
   ideas will be translated into a story told by line drawn
   characters conveying your ideas.* It might not even contain any
   words; and of course you will have the ability to modify it
   before sending off to be sure it conveys you correctly. You will
   also have the ability to place *your* style of logic into the
   system itself so it can perform tasks in the ways that make
   sense to you. In other words: Programming willl be a key part;
   but something akin to a much upgraded future version of the MIT
   SCRATCH project; an extremely powerful visual programming
   environment, aimed at 9+ but being used even by people who are 5
   and 6; and some of the things created rival commercial games;
   precisely because they were given a set of basic but powerful
   tools to automate the tasks necessary in a game, in a way that
   makes sense for their way of thinking. I'm not saying that
   Minecraft itself is the model; or that things will be
   programmable blocks (although I imagine the first iterations of
   a concept like this will start out that way), but rather, the
   idea of have a combination of Object Oriented Logic style logic
   flow, ALONG WITH something they keep TRYING to get rid of out of
   programming but really works more like how our minds work: The
   GOTO. Akin to a teleport, it allows you to jump to any part of a
   system at any time that is necessary;* It is akin to a click on
   a hyperlink on the WWW; where you are not limited to containers
   within containers inheriting features but the ability to jump to
   ANY part of a system just as our mind jumps from analogy to
   analogy, almost seemingly randomly sometimes. Immersive, virtual
   3D, no limits to the kinds of control you can have over what you
   input, how you receive feedback from the system, and what the
   internal processes are that you wish the computer to perform,
   and when. So "who will win?"* I suspect a dark horse will emerge
   that will blow them ALL away AND they won't see it coming. It
   will be easy enough to for a 4 year old to use; sophisticated
   enough for anyone to be able to make the Interface look and feel
   the way they wish and powerful enough to do anything with
   anything. Example: If I wanted my computer to behave like Tandy
   Deskmate from 1990, I could set it up easily like that. If I
   wanted to use long forgotten VAX/VMS typed commands to operate
   the system, I'd be able to do that. If I wanted to stick with a
   desktop metaphor because I'm comfortable with that, I could do
   it. If I wanted to create the Inside of the TARDIS and operate
   my computer from within there, I could do that. There would be
   no file saving per se; more like a state system which allows
   infinite undo and returns to any point within the system. Too
   many constraints in all of the systems currently available.
   Sorry I couldn't give you a simple answer; I'm 42; got my 1st
   computer at 11 yrs old; and as awesome as the changes have been
   through the last 31 years, some of the changes haven't been
   good; and a lot lot of it, ,basically hasn't changed at all.*
   Human/computer interface has bothered me from the beginning; I
   work within whatever I find myself facing; but there's a lot
   that needs to happen.