Is there a light behind the camera? Is it supposed to be a window or something like it?
I see a window frame over the by cupboard, I assume that is the main source of illumination and I think you will get a nice daylight feel if you make the light behind the camera softer/weaker. Thats a matter of taste I guess though.
Very rarely will you get the same amount of light from two opposite windows, unless there is a lot of snow outside.
Aaah, Keen, you have me there. I confess to laziness on my part! OK, glass going up in front of the poster at the next session.
Monsterdog, I added an area lamp behind the chairs instead of the reflector suggested by sundialsvc4 in the second post, since a reflector would have seriously affected the render time. It is distinctly yellow, mind you, and can be assumed to be a lamp in the corner behind the chairs. Or something.