Aviator 4.6L - Rough while in Drive and Stopped

[rockd]

Recently got my '03 Lincoln Aviator with the 4.6L V8. When the truck is in "drive" and not moving (like at a red light), it idle's pretty rough. However, the slight shaking goes away when you put it in park or when you start moving.

I've been leaning towards changing the plugs and coils, but could this be caused by anything else?

Thanks!