We can look at current technology to predict trends for future technologies. These are the areas that startups and current computer companies should focus on.
Voice recognition and speech synthesis, being able to talk to a computer and have it talk back. This was made popular in "Star Trek" and IBM Viavoice, and Dragon naturally Speaking made it work even if all the credit is given to Apple for Siri. Windows 7 for example has limited voice recognition and speech synthesis. This is good for the blind and nearly blind, as well as people who are disabled and cannot type or in some cases cannot speak. It makes it easier to write books by narrating the words to the computer instead of typing them out.
Handwriting recognition, this has gone back to the 19th century but has never been perfected. The Apple Newton used it but it was awful, always getting the wrong words. The PalmPilot solved the problem by using shorthand. With modern touchscreens where the finger is used, one cannot write very well with a finger so a stylus is needed to work like a pen for this to work. The best use of this technology is to scan in handwritten books and documents so they can be converted to text and indexed and searched.
Vision and movement using cameras. The XBox Kinect may not have been the first, but it is popular enough to use as an example. By moving your hands or other body parts video games can be played, but the potential for real life solutions is almost endless. "Minority Report" showed a system of hand gestures to control a computer. This will help the deaf and hard of hearing who use ASL or some form of sign language to have the camera turn singing into words for use in documents or operating a computer.
Robots, we are not using them as much now because of cost. Making robots cheaper would be a key to selling more of them. Finding a use for them besides factory work, and cooking might be profitable.
Artificial Intelligence, even if your AI web robot can't pass the Turning test it can still have uses. Most commonly asked questions can be answered by a AI web robot. Think of it as an automated FAQ page. The AI web robot can be programmed for other things such as verifying identity and providing minor tech support issues.
3D Printing, once this becomes cheaper it will really take off. It will allow small businesses to make plastic and metal items using 3D printers, and allow large companies to automate fabrication of parts to giant 3D printers. Instead of tooling up a factory to make a few parts, the 3D printer can just print them in a few hours, reducing the cost of fabricating those parts. After a while a 3D printer will become so complex it can print electronic parts and that will revolutionize the computing industry.