Mint Rations Silver Eagles
Source: Numismatic News (1/10/11)
"Authorized Purchasers must buy one 2010 coin for every five 2011 coins."
The Mint calls the rationing method "allocation."
Also, in order to prevent Authorized Purchasers from ignoring the remaining 2010 supply, the Mint says that the coins are being sold off on a 5-1 ratio basis when ordering 2011 coins. That means the AP's must buy one 2010 coin for every five 2011 coins they buy.
This system was used at the beginning of 2010 as well.
The supply situation for gold is much better. There is no rationing for the one-ounce gold American Eagle. AP's can order as many 2011 coins as they like, however, they must take the 53,000 leftover 2010 one-ounce gold Eagles on a 4-1 order basis.
How long rationing of the silver Eagles will last is not known. Last year it continued until the end of August.