Some good picks, Celine... And yes, if you want to name the most important figure right now, it is without a doubt Iwata. He restructured Nintendo's software development, resulting in them making more games, and he oversaw the DS and Wii, which have a chance to demonstrate the biggest across-the-board domination the industry has ever seen. He even personally secured the creation of a new franchise, which has gone on to sell 10 million copies (Brain Age). Seemingly Iwata can do no wrong right now.
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.