I talked my wife into going dark with our walls, we're using a "painted leather." It's a dark brown so that should help my projector out with the picture. My question is should I paint my ceiling the same color? Will I notice a big difference? We were just going to paint it normal ceiling white.

Keep in mind this is basically my new "family room" so it will be used on a daily basis. I am however a night owl so I love watching tv/movies in the dark.

I wouldn't paint the ceiling white, but you don't have to paint it the same color as the walls. Try a lighter ( but darker than white ) color that compliments / goes with the wall color. That's what we did in our theater using shades of brownish gray. The two tone look can work well for a home theater and look really sharp in general from a home decorating point of view!!