Looks OK, as far as it goes - make sure it's centered side to side in the room, and that everything is symmetrical. Do NOT put the speakers/your head at a height that is centered between floor and ceiling, however - too many cancellations/peaks there.
Speakers should never be against walls - if you're in a hurry, 2-3 feet minimum away from any wall will work OK -
If the room is big enough, try to keep at least 11-12 feet from your head to the rear wall, otherwise you need to absorb it. Longer than that, and diffusion (bookcases, RPG, QRD's, etc) is good.
If you want to be REALLY anal (haven't tried this, it might be FANTASTIC...)