Prediction. Computers, as we know them: boxy devices with a variety of ports and discreet single-function I/O devices such as are going to disappear in the next decade or less.
Here's how I see the development as it has gone and will go.
1st generation 1960s-1970s?
Dumb terminals attached to big computers in separate rooms, tended by specialist staff. Control of software is with command-line interfaces and modal control-key interfaces, e.g. vi. Unusable without training and considerable learning; users confined to specialists.
2nd gen. 1980s?
Textual interfaces on micros, driven by keystrokes. Needs learning, but it's easier. Systems come with manuals, keyboard overlays, help systems. Usable by hobbyists and nonspecialist staff with some training. Uptake grows.
Gen 3. Late 1980s to early/mid 1990s?
WIMP GUIs. Mouse as primary interaction. Early systems monochome; colour used decoratively rather than informatively. Quite discoverable - documentation starts to shrink, become optional. A lot of uniformity in design, leading to lawsuits. Usage becomes widespread; people with the suitable inclinations or requirements teach themselves to use computers and use them for a broad range of activities, including leisure and the arts.
G4. Late 1990s-early noughties?
Sophisticated WIMP GUIS. Programs develop specialist extensions to the WIMP and designs of WIMPs diverge a lot. Specialist WIMPs appear, such as in CAD, 3D design, games design, which are as complex and non-discoverable as anything from the 1970s and earlier. Literacy in GUIs is assumed, which increasingly disenfranchises many people.
G5. Late noughties.
The rise of the Web. Internet access becomes the dominant driver of computer use. Web pages rapidly grow in sophistication and all traces of common UI design go out the window. 3D-accelerated multi-colour GUIs start to appear; colour and shading and transparency are used to enhance the GUI and to convey information. (e.g. red wiggly underline = misspelling; green wiggly underline = grammatical error.) Internet users are now over a billion; many solely use social networks, completely eschewing older communications channels such as email. An entire generation of young adults in the West have grown up with Internet-connected computers as purely leisure devices, toys not tools. Lack of computer literacy severely impedes adoption of modern computers for many, especially older people. Talk of "digital disenfranchisement."
G6. 2007 - 2012/2013 or so.
In hindsight, the last days of the WIMP. Right-clicking and 3D are near-universal; multitouch finger-driven UIs starts to appear in specialist devices. Late noughties. Immediate, instant, very simplified interfaces start to appear everywhere on consumer devices; the primary and often sole interface device is a touchscreen and a finger or fingers. WIMPs are now labouring to keep up, leading to things like "ribbons" and context-sensitive toolbars that appear and disappear dynamically. Broad differences starting to appear between different devices, platforms and manufacturers; recently-dominant companies & platforms that fail to adapt struggle and die, e.g. Nokia, Symbian, Palm.
GUIs are now very rich but very complex, with animations, fades, zooms and animated 3D objects and effects. It now takes time and effort to learn to use them effectively; thriving aftermarket in manuals, as these are no longer supplied with software at all.
Slate-style devices start to become a significant sector - inside 4y, the primary computing device for a quarter or more of Internet users. These do not use a WIMP at all. Users of traditional platforms deride finger-driven computers as simplistic, limited, toylike, crippled, and point out the resemblances between their richer platforms and the new simple ones.
Widespread adoption of finger-driven slate devices by people who previously could not use computers at all, or only in extremely limited ways. With no knowledge or training at all and little or no online help even present in the new systems, people can surf, take and exchange pictures, sound and video clips, talk, play games against one another and so on. Wireless internet access is seen as a basic human right; deprivation of it associated with rioting.
Apparent drop of online literacy reveals that people who have not written since school are now writing and communicating online. Increased replacement of text by video; sites such as Youtube and the Khan Academy and ubiquitous podcasting replace simple text-based information sharing with amateurish audio and video clips, labelled and tagged illiterately if at all. Younger users find this more accessible than written information.
New generation of keyboard/mouse-driven computer OSs adopt slate-style interfaces (as per the early signs seen in Mac OS X 10.7, Windows 8, Ubuntu 11.x et seq. There are no menus or windows, no way to close applications, no direct access to the filesystem. Sometimes the new interfaces are optional and many experienced users dislike them. Novices don't even notice. For users not interested in the technology itself, simple slate-type devices replace conventional "personal computers" for everyone except power users or developers. Workers in organisations issued with corporate boxes do not get to choose, but are now a minority part of the computer-using community. Speech and facial and bodily-gesture recognition starts to be used as a control system in ordinary use, not just in gaming.
G8. late twenty-teens (2017-2019/2020.)
Slate-type, finger- and speech-driven computers of various sizes utterly dominate the mass market; phones, gaming devices, media players, ebook readers all have merged into cheap commodity sealed units, not user serviceable or upgradable and completely unusable without broadband internet. Keyboard/mouse-driven desktops and laptops are confined to specialist niche markets in business. "Desktop" OSs merge with slate/tablet OSs; no distinction is visible and things like "WIMPs", "disks", "files", "directories" are a fading memory. Software distribution is entirely electronic; physical media disappear, largely including for the music and video industries.
2020 and beyond
Devices such as "desktops", "laptops" and "games consoles" are historical, as rare as serial text terminals. No remaining division between "computers" and "screens" - they are the same device - or between "disk" and "memory".
Sharp division apparent between technical specialists and hobbyists using computers with vestiges of windows and command lines and other legacy technologies, used only in development and for building and administering servers. Legacy tech such as magnetic or optical disks only used in servers; most computer users have never seen one, nor a "port" or "cable". Ordinary computers are sealed, solid-state, battery-powered devices, charging and communicating wirelessly; owners would no more increase their devices' memory than they'd rebore the cylinders of their car engine for greater cubic capacity. Small numbers of hobbyists build their own machines from components and exchange "software" and "files" as nostalgic entertainment.
The notion of the "PC" has less time left than the time since the turn of the century. Before this current decade is out, various sizes of sealed, disposable computer - just a touchscreen that responds to gestures, facial expressions and voice - will have completely replaced the PC and the Mac in all except specialist niche markets, where they are used by less than a tenth of a percent of "computer users." Existing media printing, recording, publishing and broadcasting companies will have mostly ceased to exist unless they have transformed themselves into a direct-to-subscriber model; there are few remaining TV channels and other mass one-to-many channels remaining, and these are seen as the refuge of the extremely poor or disadvantaged. Production of books and printed media becomes a specialist minority craft activity, like sculpting or painting on canvas.