Yes, it will make a difference. Not so much in the total render time per frame, but more in the time that it takes for you to perfect an animation. You will find huge time savings come available in the compositing stage because you don't have to go back and re-render stuff like backgrounds. And it's a huge time saver with static, i.e. non-moving cameras because rather than rendering out the background for each and every frame, you only render it once--on the first frame.

If something doesn't change from frame to frame, then why bother re-rendering it for each frame?

RJ