I think Peter is analog to Sylar: both have abilities that make them absorb others powers. Sylar can learn how they work while Peter is something more like osmosis.
I think Peter stays with the "embryo" of the power, then he could later fully develop it (my theory).
When Mr. Bennet talks to Sylar about "everyone we know have only one power and what the hell will happen with someone like you", I think the answer is Peter (a bomb man).
Sylar gets the powers and "install" them, no problems...but Peter doesn´t have a clue about what is happening.
Call me crazy
