It will be a Federal crime to trade in gold & silver after the 15th.
That isn't exactly the case. Deferred (Delayed more than 28 days) delivery of foreign exchange (Forex) sales are the only commerce affected. No other precious metal exchanges, personal
or en masse are effected by Dodd-Frank.
If they are a coin dealer who sells gold, silver, etc., and they deliver the product in 28 days or less, the Dodd-Frank Act should not affect them as the seller or you as the buyer.
Still, I expect prices to take a jump as it's a scary scenario being set up.
I expect little people like us will, if anything, just get our shit more quickly.
EDIT: if you buy from Apmex, Kitco, Bulliondirect etc. for instance, nothing changes. If you are doing personal trades, nothing changes. The primary real effects of Dodd-Frank on metal exchanges are making it illegal to take more than 28 days to deliver.