I would say 1 meter is at the lower end of the space you would want to use to interact with a GUI using your hand as a pointer, regardless of accuracy. Once you get below that you are mapping small hand movements to big movements on screen and you get the reverse effect of having bad camera accuracy. A gestural based system would be better for smaller hand movements.
To be comfortable, you would want to use, IMHO, a two hand system where each hand can interact with an imaginary plane positioned in front of you, centered on the head. This allows for a larger area of interaction, and is somewhat intuitive.
As far as accuracy is concerned, we shall see.







