The interaction betwenn the two sides of the edge is surely awesome, but not always necessary.
It would be very useful to have the ability to close the "Reader" process when not needed.
For example, if you are using the edge only as a netbook, the cpu and memory resources are partly vasted to run the readerin background.
Closing it would make the device more responsive and usable while using flash lite (from the upcoming update) or games.