Rigify is using all Layers I'm curious about a problem (?) that I'm having with the rigfy add-on.
First of all, I have this model with the meta-rig adjusted


Until this moment is everything normal.
But when I click in the generate buttom, all the layers are occuped:



The configuration that (I think) is responsible for the layers occuped is se as default:



I think this is a problem because in the videos I saw it didn't occurred.
Someone knows about this (little?) problem?

I'm using blender 2.74.

Sorry for my poor english and, since now, thanks.
Bone layers  are different from object layers.
As i can see from your screenshot, Rigfy has correctly put the bones in different bone layers, to help selection groups when animating, but the "problem" you point at is the fact that all object layers appear "occupied".
You can go to the outliner window (or create one), change the pop-up menu from "All scenes" to "visible layers", select one object layer at time and read in the outliner what's inside, to understand the thing, that - I don't think - is produced by Rigify.

Also, before pushing the "generate" button, apply the scale (Ctrl A) to both your model and the meta-rig.