The US Mint website now states:
The United States Mint has eliminated the credit and debit card purchase of $1 Coins through its Direct Ship Program effective July 22, 2011.
The announcement has since ended the benefit of ordering the $1 coins, which allowed you to rack up credit card rewards (miles/points/cash back). They have remove the incentive for people to order these coins. I suspect that there will be a huge decline in the demand of the $1 coins after the elimination of the credit card purchase. Baltimore’s reserve bank is sitting on an increasing pile of dollar coins.
I made decent use of the credit card program while it lasted, although I was not aggressive as some people who have ordered hundreds of thousands of coins. I also did my share to help circulate the coins by promoting and spending them.