Back in the year 2006, Yuki seemed boring and uninteresting as a character. Here in the year 2009, I feel that she is, weirdly, growing on me.
Perhaps 2009's Yuki looks more MOEish, or maybe it's because of the imminent "Season 2". Her subtle actions, emotionless facial expressions; these little details enhance her image as a mysterious yet dependable character.
Finally I understand the fanboyism over Yuki that permeated the Otaku's scene for 3 whole years.