Input: We currently have mouses, keyboards, and touchscreens. Sensors have been alluded to. But the implications are much larger than has been explained. The reason is because sensor is a big word. Creating the architecture that allows any object to act as an input device to a computer program is a daunting task, but will certainly merit "trend" status.
Brain-Computer Interface (BCI) is currently only in research labs and unprofitable startups. But the concept is proven. With some fine tuning, you can actually use neurological output to input commands to a computer. Basically, that means mind control, which is cool.
Computer Vision could be considered a subset of "sensors" but it deserves a mention in itself. In China, facial recognition has been ubiquitously deployed such that anyone in a public place can be identified. This is scary. But TechCrunch-enthusiasts can think of it as a system that automatically updates your foursqaure.
Skin makes a unique frequency (inaudible sound) depending on where you touch it. Researchers at Carnegie Mellon University have developed a way to use the human body as input device. They call it Skinput. Google it.
Output: We currently have desktops, smart phones, and tablets. The Holodeck is a room that combines virtual reality with Haptics technology and uses all types of crazy sensors to give you the illusion that you're "in" the internet. Death to the web-page.
IRL HUD's will be the norm in the future, a notion endorsed by famous men like Dr. Michio Kaku. It will begin with Google's glasses(augmented reality device), but over the next two decades, it will progress into contact lenses that contain all the parts of a computer and a high-resolution display of quantum dots, and it will be controllable entirely by thought. You will also be permanently connected to the internet, and you will be able to send all your thoughts to it instantly, as well as receive those of others. Memory won't be a problem anymore because you'll be able to automatically save your thoughts to the cloud. In the near future, the glasses + tablet combo will decrease sales of smartphones as they become obsolete.
Computation: We currently have Independent, GPS-enabled, CPUs
Human-Computation is the art of conjuring free labor and the science of putting it to good use. For example, it would take a man a million hours to read Wikipedia in its entirety. With a million people, Duolingo could translate it in its entirety in 80 hours. Another example would be how the machines harvest human brains in The Matrix (1999 movie).
Context-Aware Computing has to do with (1) where you are; (2) who you are with; and (3) what resources are nearby. Although location is a primary capability, location-aware does not necessarily capture things of interest that are mobile or changing. Context-aware in contrast is used more generally to include nearby people, devices, lighting, noise level, network availability, and even the social situation, e.g., whether you are with your family or a friend from school.
Grid Computing is a term for distributing complex calculations throughout millions of idle computers. An example is the SETI@home project that uses millions of computers on sleep mode to search for extraterrestrial life. We need more big ideas like this.
Privacy and Identity
Everywhere you look it can be seen that our identities, preferences, shopping habits, likes, histories, images and intellectual properties are either under attack or have been exploited. The next big service will be a central place or mechanism to store and control all your information and data: who has access to it; who has it already; what they are doing with it; and ways to automate and authenticate you so that you can insist on your rights to demand its removal. Having this standardised and simplified will help people understand the dangers more and give them the tools to tackle it. Until this problem is addressed, most ideas mentioned on this page are simply new services that will further expose our vulnerabilities.
Virtual Reality
Of course Virtual reality will become mainstream in 2015. Gamers, military, enterprise etc. will find solution to problems by way of virtual reality. Gamers will be part of the actions in games; and the millitary would experiment field tests like flight simulation and train new recruits in the skills and techniques necessary to function effectively using virtual reality headsets.