It is much more likely that the government will outlaw guns and ammo rather than gold.
In a SHTF situation, the government will clamp down severely using powers of the Patriot Act, FEMA, the National Guard, and executive orders from the President.
We are only 1 vote, 1 Supreme Court Justice appointment, away on the Supreme Court to have it ruled that American citizens do not have any individual right to bear arms.
Whoever is elected President in 2012 will appoint at least 2 judges, and will thus ultimately decide if Americans are allowed to possess guns.
In a SHTF situation, the government will clamp down severely using powers of the Patriot Act, FEMA, the National Guard, and executive orders from the President.
I don't mean to fault you for your out-of-box thinking - more of which we need - but that scenario's becoming more unlikely over time. You know why? With the increasing militarization of the police, guns become (relatively speaking) less and less of a threat to them. As long as the constabulary is much better armed than the armed citizen, the armed citizen won't be much of a threat to the constabulary.
Also, in combination with the above point, it's good PR to let people keep their guns. Better that the average armed citizen has no obvious cause to get "unruly."