Exactly
Chris, the Brown ammendment passed both the House and the Senate with bi-partisan support.
It includes impactors form both asteroids (like asteroid Apophis) and comets (ike the 64 fragments and dust stream of comet Schwassmann Wachmann 3). Dealing with them is President W. Bush's job, and NASA Administrator Griffins'. While those are the currently known problems, Brown also makes them responsible for finding the currently unknown.
That's why they get paid the big bucks.
While I hope this clarifies things for you, I doubt it will.