Well the more rectangular it is, the harder it'll be, and the more you'll have to shift the balance, but it'll work.
If the room is more square, put the rear speaker on the wall with the bed, shifting more away from the corner, the more square it is.
This is how I have my room setup (with the computer in a corner) and it works flawlessly once you get balance sorted out.
EDIT: higher speakers will probably be better. I have mine mounted at 4.5 feet for the fronts, and 6 feet for the rears. Use wall mounts with swivels so you can aim them better.