According to a USA Today/CNN/Gallup poll:

25% of Americans have never heard of Karl Rove.

Only 51% of the country is following the Rove affair at least somewhat closely.

Of the people who are actually following the affair (ie, excluding the no opinion people), 32% think Rove did something illegal, 49% think he did something unethical, but not illegal. In other words, 81% think he did something unethical.

Just over half of the people who are paying attention think Rove should be fired. 61% think he should resign.