Why fuzzy? Read below.
Using a flocked surface, noctua claims it creates a turbulent boundary, improving airflow over the blades while lessening clashing air waves, similar to the way dimples on a golf ball cause lift.
Initial testing shows improvement in both airflow and noise. I don't know the practicality of this, though, as cleaning dust from these things might be problematic.
Ugly, but effective. Typical noctua.