Brooke Shields, the model of the 80s, reignited the trend of bushy, fuller eyebrows and has maintained this look. The likes of Helena Bonham Carter, Demi Moore and Jennifer Connelly have always had a thicker arch. I think it must be a brunette thing - us brunettes would just look odd with overplucked lines.
Eyebrow idols of today, Kate Middleton, Camilla belle and Dita Von Teese are redefining what's beautiful.