Anthony
Professional Speedcuber
Durben Virtucio is fast at 3x3, really good at 4x4, and he's young (turning 13 in November, I believe).
And he's only been cubing since February 08. Which is insane.
You also have to take into consideration how much cubing each person does per day. I have no idea how much Durben cubes, but according to Sittinon, Piti makes sure he does over 1000 solves every day.