I know that touchscreen desktops have been around for awhile, but I don’t think any of them have really blown up, nor do I know anybody who actually owns one (possibly because I’m still a college student and am married to my laptops). I found it interesting that Dell just released an all-in-one Inspire One 2320 touchscreen, which is essentially just a really big tablet (23 inches!) that connects wirelessly to a keyboard and mouse. Its specs are right up there with its competition: Intel Core i5 processor, 6 GB DDR3 RAM, 1080p resolution, and a TV tuner for only $1k.
Maybe it’s because I only really use a laptop, or maybe its because of things I’ve learned about user interfaces from experience and/or classes, but I still find the concept of touchscreen desktops odd. It may be slightly faster to be able to touch things on your screen as opposed to using a keyboard/mouse, but I think tablets (and phones) are the only technologies that hold the right to have touchscreens. If the item you’re using is too big to comfortably hold like a book or to set down on a desk and not be obnoxious to everybody around your personal bubble, it’s probably easier just to use those “old school” input devices to control it.