Normal OSes were designed with a mouse and keyboard in mind, which is a big reason why Microsoft's original Tablet PC's were such a huge failure - they tacked o

Normal OSes were designed with a mouse and keyboard in mind, which is a big reason why Microsoft's original Tablet PC's were such a huge failure - they tacked on some interface elements that were supposed to make it easy to interact with a pen, but it was never more efficient than using the mouse and keyboard. The reason they caught on this time around was because Apple designed the tablet around the fact that multi-touch would be the only way people would ever interact with it. Given that iPads are flying off the shelves, you have your answer as to why tablets aren't getting normal OSes.