Now you are right we don't need a 100ghz computer, but you have to think in the future. You could tell your computer what you want it to type, in real time, while it automatically audibly suggests changes to you paper, and offers new relivent information for your essay, in essence it writes the paper and helps you improve it, all while doing your taxes, downloading the latest hollywood movies, downloading your digital movie vmails, having your computer frag the hell out of your friend on UT 25, download your favorites artists' new album, and allowing NASA to use all the spare cycles for designing the 5th generation RLV on CAD, and any other normal activities you might do with your computer. You must think big if you are thinking about the future. Maybe someday we will get to the point where computers have so much excess power that we can stop worring about ocing and getting the latest hardware that we can focus our attention on the things in our lives that truely matter, spending time with our family, and friends. Read my reply to your post in the HT forum here.
Life is complex.
It has real and imaginary parts. Real time voice and vision recognition can be executed. It could almost be like having your own personal assistant. Or maybe you want to do some research, and you tell your computer to go search around online and find the most relevant information for you. Things like this can eliminate some of the tedious details of our lives, which I believe is a fairly exciting possibility.