Looks like your front speakers are going to be stuck in the corners of the room . Not an ideal position for them but if that is all you can do...well then you just have to deal with it .

Gonk is right the windows are going to let in a lot of light . I am familar with the type of DLP (Samsung) you are using . It should not be too much of a problem so long as the sunlight is not directly on the screen .
The windows could pose a second problem with deep bass and vibrate at certain freq's . But the re are plenty of treatments you could use to tame the windows .
I would be most concerned about where you plan to place the back wall in order to cut the room in half . Avoid a square shape at all cost . A cubeshaped room offers the worst room acoustics possible . Go for more of a shoe box shape when building the rear wall . Make sure all dimensions width, height and length are are different and not multiples of each other . Looks like from the photo that the room is obviously wider than it is tall so you are good there . About 1 and half times the width is a good starting point for the length . The height your pretty much stuck with . Just remeber shoe box .
Gonk is right dimension here would be useful .
Also there are several online room calcs which can tell you roughly if the dimension you plug into it are favorable or not . I will try and find one for you .