Balmer looks serious and even a bit dull, but in fact his personal style is very strong. We can see this from the witty remarks that defused the situation after he was hit with an egg, as well as today's "I'm a PC" roar. Some people commented on him: "Balmer is an excellent businessman, smart and tough, his personal style is very impressive."
This video of Balmer's "I'm a PC" roar is reportedly part of Microsoft's third heavily promoted advertisement, but it's unclear why this segment wasn't played during the actual broadcast; perhaps someone thought it was too intense.