Enhancement-mode gallium nitride transistors have been commercially available for over five years and have infiltrated many applications previously monopolized by the aging silicon power MOSFET. In this paper, we discuss the state-of-the-art and the expected progress of GaN technology over the next few years, showing that Moore's Law is alive and well in the world of power semiconductor technology. We begin by enumerating the advantages of GaN over silicon in terms of performance, cost, and reliability.