If some company made a device that truly was the best of both worlds, sure, I would buy that. But the tablet / laptop hybrids avaiable right now are more like the worst of both worlds.
I think the real issue with building a hybrid that is the best of both worlds is the screen size. The optimal screen size for tablets seem to be 10 inches and below. Bigger than that, and the screen is too big to hold comfortably in hand. The optimal size for laptops, however, is 11 inches and larger. Any smaller and the screen becomes cramped for desktop applications, but even more of a problem is that the keyboard has to be the same size as the screen. Any keyboard that fits a screen below 11 inches is too small to type comfortably on.
So while I have no problem with the concept of a hybrid device, I'm very skeptical that this concept can be executed well in real life.