I just checked my D300, wiped down the screen with a microfiber cloth. I dont see any dust and not 100% sure about streaks. its a cloudy day outside so i tried a flashlight at various angles. It seems like i could see some faint streaks in a vertical line just south of center of the viewing screen but very feint. As they dont seem to affect viewing quality, at this point i'm not going to worry about it.
____________________________________________________________________ When no one is looking, Pigs can walk on they're hind legs